Top Banner
Open Research Online The Open University’s repository of research publications and other research outputs The Hypanis Valles delta: The last highstand of a sea on early Mars? Journal Item How to cite: Fawdon, Peter; Gupta, Sanjeev; Davis, Joel M.; Warner, Nicholas H.; Adler, Jacob B.; Balme, Matthew R.; Bell, James F.; Grindrod, Peter M. and Sefton-Nash, Elliot (2018). The Hypanis Valles delta: The last highstand of a sea on early Mars? Earth and Planetary Science Letters, 500 pp. 225–241. For guidance on citations see FAQs . c [not recorded] Version: Version of Record Link(s) to article on publisher’s website: http://dx.doi.org/doi:10.1016/j.epsl.2018.07.040 Copyright and Moral Rights for the articles on this site are retained by the individual authors and/or other copyright owners. For more information on Open Research Online’s data policy on reuse of materials please consult the policies page. oro.open.ac.uk
18

Open Research Online › 56400 › 1 › The Hypanis Valles delta_ The last... · Open Research Online The Open University’s repository of research publications and other research

Jul 04, 2020

Download

Documents

dariahiddleston
Welcome message from author
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
Page 1: Open Research Online › 56400 › 1 › The Hypanis Valles delta_ The last... · Open Research Online The Open University’s repository of research publications and other research

Open Research OnlineThe Open University’s repository of research publicationsand other research outputs

The Hypanis Valles delta: The last highstand of a seaon early Mars?Journal ItemHow to cite:

Fawdon, Peter; Gupta, Sanjeev; Davis, Joel M.; Warner, Nicholas H.; Adler, Jacob B.; Balme, Matthew R.;Bell, James F.; Grindrod, Peter M. and Sefton-Nash, Elliot (2018). The Hypanis Valles delta: The last highstand of asea on early Mars? Earth and Planetary Science Letters, 500 pp. 225–241.

For guidance on citations see FAQs.

c© [not recorded]

Version: Version of Record

Link(s) to article on publisher’s website:http://dx.doi.org/doi:10.1016/j.epsl.2018.07.040

Copyright and Moral Rights for the articles on this site are retained by the individual authors and/or other copyrightowners. For more information on Open Research Online’s data policy on reuse of materials please consult the policiespage.

oro.open.ac.uk

Page 2: Open Research Online › 56400 › 1 › The Hypanis Valles delta_ The last... · Open Research Online The Open University’s repository of research publications and other research

��������� ���� ���������������������������������������������

��� ����������������� ���������!�"#$�!%&"�%'$!�("(#)!$�$(�'!'�%�")%*'("%))$#+�*�+�!&#(����$("�)")%*���&&*%(#()����'*)��#(�%(%*+ ���'

,-./0-1234-15/-.67895185:5//5.;<==>?=@AB??<C?D@EFGHIGHJKLJHJMNMLKMOKIMHPQLIGQIRLSIQH,-./0-1234-15/-.67895185:5//5.;TTTUIKJINLISUQFVWKFQMHIWIXJKY05 Y05Z6[-19; 254/-\]-445; 4-;/090;/-12_ _1-;5- 5-.46a-.;b35/5.c-d2_1-efg7-1h55ijk[/-lgm_54ano-i9;8gp980_4-;Znq-.15.2gm-8_lrns245.5ga-//05dtnr-4u5-gm-u5;cnr544vvv5g35/5.anj.912._28g,449_/75/_1wp-;0-xyz{{| xy}~�y~��{��z��}y�| �z~��~���}�~��}�����|�{���||��}|�{��~��~�����������l�~�����~��{� �{��{���{��{������zxy}~�y~�������}�~~�}������~�}�|�{||~�~ x��������8�~�����~��{� �{��{������z �}��{��xy}~�y~��������| ���~�����{� ~||¡{����~��}���{�� x��¢£����2�~�����~��{�¤~{|{�}y�|xy}~�y~�����~����~�xy}~�y~�~��~�� ��}�~��}��x���~ {� ¥{�¦���~  ¤~�~�~{���~�{||~�~�}�y|~�¤~�~�~{��¥§ ¢��x�5xyz{{| �©�|{���}{��{�����z���x��y~ ��}ª{��x���~��}�~��}����x�£ ¡{{��«¢��¬§�~���y~��||��~��~���¬¢�¬���x����{�~��x��y~ �~���~�¡~�~��yz����~yz�{|{�� �~�|~�|���§���­§���{{�� }®¦��~�z~�|����¯°±²³´µ ²¶·¸ ¯¹º±°¯³±���}y|~z}��{��»[email protected];52 _.u ?¼mk46?=@As885[/52?½mk46?=@Asi-94-l45_14915¾¾¾¾,29/_.\sn¿91�~� {���»a-.;a-.; 5_4_6a-.;_85-1254/-Àki9-4Á15_ /05u_;/8_1/51/9_k;06[_/05;5;91/05 5_4_98-4 1_./05.109;/_.6_ a-.;9;d05/05./054_d4-12;5i5.8_1/-9152-1_85-198d-/5.l_26ns.k-l46g/05l5;/5i925185_.-1_85-18_u5;._u/05[.5;5185_ ;529u51/-.6 -1;-._k12a-.;Â2980_/_u6l_k12-.6gd0980;5[-.-/5;/051_./05.14_d4-12; Z6[-19;._u /05;_k/05.1 /05 /050904-12;nZ5.5d525;8.9l5 [-4-5_5_u_.[0_4_6_]-445;;529u51/ ;529u51/-1g/054-.5;/ -18_u[45¾.5[_./52_1a-.;>-.5-ÃĽ=Åu?BnY09;0-;-15¾/51;9i58-/80u51/>DÆÇÈ@=<Åu?B918_.[_.-/91Z6[-19;-12p-1529]-445;g/0-/d5;0_dd-;-8/9i52k.91/054-/5wp_-809-1É5-.46wZ5;[5.9-1 4_l5w[5.9_2 ¼n½j-Bn _>Ê Y05-18_u[.9;5;-;5.95;;0-[52;529u51/l_295;g8_1158/52l6uk4/9[45l9k.8-/91À-/w/_[[52.925;nq591/5.[.5//054-//5.-;_.u5.Àki9-480-1154l54/;1_d[.5;5.i529191i5./52.5495na5/5.w;8-45w/098Åg;klw0_.9Ë_1/-44-65.;/0-/-.5 -.58_1/91k_k;_i5./51;_ Å94_u5/.5; i9;9l4591;8-.[;-12/0591i5./5280-1154u-.91;nY0591i5./5280-1154l.-1805;-124_l5;-.5_l;5.i52/_ /__88k.k[ -/45-;/@D=Åu._u/05_k/45/_Z6[-19;]-445; [._.5;;9i5-1225;8512Ê<==u91545i-/9_1nY05 l-;91d-.2 /05-2i-185_ 80-11544_l5/.-1;9/9_1.58_.2;25[_;9/9_1-12-ik4;9_1-//05u-.91_ -.5/.5-/91 ;/-1291 l_26_d-/5.g-;;ku91/05545i-/9_1 l-;91À__._/051_./05.1[4-91; 9;;/-l45nq591/5.[.5//05Z6[-19;;529u51/ -1/_.5[.5;51/ --1-18951/254/--;_[[_;52/_ Àki9-4-1;6;/5uns/9/;4_8-/9_1-//052980_/_u6l_k12-.6g/05Z6[-19; /0-/]-445;-1;6;/5u9;/_[_.-[098-446 /__[51 Ì0.6;534-19/9-C-15¾/51;9i5[4-91 _[51;91/k.1 4_d4-12; /0-/91/_/054-.5.1_./05.1 l-;91nq58_184k25 /05_l;5.i52 _[._.-2-/9_1 -1l_295;d-;2k5/_l-;91d-.2 -18951/;0_.54915.5/.5-/_-1 l_26_ d0980 -8._;; Ì0.6;5d-/5. 5¾/51252 -/45-;/34-19/9-nj9i51/05_[51/_[_.-[06g9/9;[4-k;9l45/0-/ Z6[-19;/05 -1;6;/5u.58_.2;/055¾9;/5185g4-;/090;/-12g-12 -12.5/.5-/_ Ì0.6;5-4-.5;5-91 34-19/9- [5.0-[;5i51-1_85-1/0-/Í4452 1_./05.1/05[4-91;_ a-.;nÎ?=@AY05sk/0_.;n3kl49;052l6,4;5i95.rn]nY09;9;-1_[51-885;;-./9845k125./05ÌÌr¿wpÌwpo49851;5>0//[\ÉÉ8.5-/9i58_uu_1;n_.É49851;5;Él6w18w12ÉDn=ÉBnÏÐÑÒÓÔÕÖ×ØÓÙÕÒq05/05. ;5-;4-.5 _.-1 0-i5_85-1gd0980u90/ 8_i5.52k[/_- ;k.-85g/09.2_/05[4-15/Â; 5i5.5¾9;/5291/051_./05.14_dw4-12;_ a-.;9;_15_ /05u_;/9u[_./-1/k1-1;d5.52Úk5;/9_1;91/05 /055_4_98-45i_4k/9_1_ a-.;n,i925185/_;k[[_./ _85-106[_/05;9; 06[_/05;9;520-;8_u5 ._u _l;5.i-/9_1;_ ;0_.549155-/k.5;91_.l9/-49u-5;>Ì49_.2-123-.Å5.g Û?==@3-.Å5.5/-4ng@ÄļBgi-445615/d_.Å; /05;5/5.u91-/91 -/_.15-. ;0_.54915;>5nngZ615Å5/-4ng _88k..5185_ [k/-/9i5?=@=Bg-12/05 254/-9825[_;9/;-/;9u94-.545i-/9_1;-._k12/052980_/_u6l_k12-.6ÜÌ_..5;[_1291 -k/0_.n�Ý��}|����~��»[5/5.n-d2_1Þ_[51n-8nkÅ>3nc-d2_1Bn

>o9s809445-12Z615Åg?=@=Bna_.5_i5.gj-uu-t-67[58/._u5/5._l;5.i-/9_1;>5nngr_61/_1 -4ng5/ ?==?B;k 5;/5¾85;;98591/05;kl;k.-85 o\Z 91298-/5;-12-151.980u51/_/05 .-/9_ -;kl;/-1w/9-44_;;_ d-/5./_;[-85>]944-1k5i- ?=@<5/-4ng Bna_.5.5851/46g/05[.5;5185_ l_k425.;4-.5 -12 0-i54_l5w;0-[5225[_;9/; l5515¾[4-9152-;/;k1-u925[_;9/;8-k;52l69u[-8/; -91/_ u-./9-1_85-1>Ì_;/-.25/-4ng Û?=@½t_2.9k5Ë5/-4ng?=@ÇBnp5i5./0545;;g9251/9691 _ [-;/ _.l_295;8_1;9;/51/5i925185 - ;/-1291l_26_ d-/5.>Ì49_.2-123-.Å5.g?==@B-/-;[589Í8/9u5_.4_8-/9_191 1_./05.1/05 4_d4-12;0-;[._i5280-445191 >Ì-..-12Z5-2g?==¼Bna_.5_i5.9/0-; 1_/l551-.k52/0-//05.5d-; 51_k0d-w/5./_0-i5 _.u52-p_-809-1w-5_85-1>Ì-.. Z5-2g-12 ?=@<Bg-12-8_425.g -18951/2.95. a-.;9;9u[495291;/5-2>q_.2;d_./05/-4ng?=@<BnY0_k0/09;91/5.[.5/-/9_19;8_1/51/9_k;g-lk12-1/ 5w0//[;\ÉÉ2_9n_.É@=n@=@ÇÉhn5[;4n?=@An=½n=D===@?wA?@ßÉÎ?=@AY05sk/0_.;n3kl49;052l6,4;5i95.rn]nY09;9;-1_[51-885;;-./9845k125./05ÌÌr¿wpÌwpo49851;5>0//[\ÉÉ8.5-/9i58_uu_1;n_.É49851;5;Él6w18w12ÉDn=ÉBn

Page 3: Open Research Online › 56400 › 1 › The Hypanis Valles delta_ The last... · Open Research Online The Open University’s repository of research publications and other research

��������� ���� ���������������������������������������������

��� ����������������� ���������!�"#$�!%&"�%'$!�("(#)!$�$(�'!'�%�")%*'("%))$#+�*�+�!&#(����$("�)")%*���&&*%(#()����'*)��#(�%(%*+ ���'

,,- ./0123456718/9:1;7<153.815671;=>?@65?6A6776;BCDDEFDGHIFFCJFKG

LMNOPOQRSTUVWXYRZ[X\ ]R_Xa X\ZUV bRWWV_cdeR\[_ ZVf[\RW_Vg[fV\ZaR\ hXfeR[_X\iVZjVV\QiSkVlVXQmYUX\VZRWn,op,SR\gQYS RWnqiV_jRWgVQ]XXVVZ ,oorst[YVVZRWn,oprSgVWZR_uVVgVYUR\\VW_RV R\g R__UXj\[\iWvV TUVQgS VwZV\ZXaZUVcdeR\[_ mRi[\R_Vg[fV\ZaR\_d_ZVf_ fReeVg[\hTxgRZRcVVnZUVyveeVzR\gyWXjVz_ZRZRWv\[Z_RVg[_Z[\{v[_UVg|}eeVaR\v\[ZQ}avSngR~{VV\s�XjVaR\v\[Z {VV\Q�avSnW[{UZ �W_X_UXj\RV ivZZV_ V�VYZRZUVXv\gVg QjU[ZVSn[feRYZQdVWWXjS RVRj[ZU[\ZUV_Zvgd QjU[ZV _VWVYZVgXvZW[\VSRWX\{j[ZU ]���ZXeX{ReU[YYX\ZXv_ _VeRRZ[X\RXv\g QiWRY~SnRZ,�f �VZ[YRW �,��of R\gRXv\g�,�oofR\g R_ fRZV[RWQuX�,�oof[\iWvV� YR\avWWhTxfX_R[Y iVaXv\g mveeWVfV\ZRd [\ZVeVZRZ[X\ [\ [_XaZUVYXWXv_ ZUV�{vVQ_SnZUV VRgV VaV VgZXZUVjVi�V_[X\XaZU[_RZ[YWVSXWX{[YRWV�[gV\YV_veeXZ_R QtRf[VljRf R\g_Vf[�R[gYW[fRZVR\ghRggXY~n UXjV�V R\g,op�Sn ZUVV�[gV\YV[_[\YXfeWVZV gV�fR\g_avZUV Xi_V�RZ[X\_�[ZUXvZiV[\{RiWVZX VW[RiWd[gV\Z[ad�\V�{R[\VgXYVR\[YgV�eX_[Z_X YWVR _UXVW[\V_R__XY[RZVgj[ZURWR{VXeV\iXgdXajRZVn jRZVRWZV\RZ[�VV�[gV\YVaX _ZR\g[\{ [_V�v[Vg�\V_vYUe[VYVXa Xa gVeX_[ZVgV�[gV\YVYXvWgiVZUVeV_V\YV _Vg[fV\ZaR\_jUVVR [�V V\ZV_R_ZR\g[\{iXgdXajRZV|[VngVWZRWR\gaXf_�VWZR[Y_Vg[fV\ZRdiXg[V_ X\UR�ViVV\[gV\Z[�Vg ]R_ivZv_v�RWWdXYYv jUVV [�V _d_ZVf_V\ZV RYRZVnaXf[\{RYX\�\VgWR~VqwYVWWV\Z qiV_jRWgVnVwRfeWV_UR�ViVV\gV_Y[iVg[\ TVidR\gkVlVX sYRZV_Q�\_R\ sVZRWn,opp �URZZRYURdRVZRWn,oo��Xvg{V �����VZRWn t[YVVZRW n,oprs s VZRWnu[{p �[W_X\ ,oo�S]XVX�VnR\ UR_@5B@7�VwRfeWV iVV\gV_Y[iVg[\�RWVYRZVv_[\{Xi_V�RZ[X\_RY�v[VgidZUVhv[X_[Zd Q�XZl[\{VX�V VZRWn,op�SmVg[fV\ZRdaR\_UR�ViVV\[gV\Z[�VgRXv\gZUVfR�Z[R\Yv_ZRWg[YUXZXfdRWX\{R\ReeXw[fRZVV�v[eXZV\Z[RW_vaRYVQ�[�YU[WWVR\gcd\V~n RWZUXv{U,opoSR\g R_[\ZVeVZVg gVWZR_n[\g[�[gvRWWdZUV_V_Vg[fV\ZRd gXiXg[V_ \XZ\VYV__R[Wd_UXjYX\�[\Y[\{ ]XXVV�[gV\YVaX RgVWZR[YX[{[\Q�RRW sVZRWn,oo�VZRWn,oorStVYV\ZR\RWd_[_ ZUVXa_ZRZ[{ReUd[\ V�vRZX[RW�V�XW[_�X_R V{[X\X\]R_UR_[gV\Z[�VgeX__[iWVgVWZR[YgVeX_[Z_R\giR_V�WV�VW [\Y[_VgYX\ZXWWVg �RWWVd__v{{V_Z[\{ZURZZU[_V{[X\fRdUR�VaXfVgReRWRVX�YXR_ZRWWR\g_YReVQhRgV\R_ sVZRWn,op��[�[R_V ����VZRWn ScXjV�VnZXV_ZRiW[_UZUVeX__[iWVVw[_ZV\YVXaR\XZUV\UVf[_eUVV�_eR\\[\{XYVR\nV�[gV\YV[_V�v[VgaXZUVV{[X\RWgV�VWXefV\Z Q�R~VXa iXg[V_gVWZR[Y_Vg[fV\Z R\g�URZZRYURdRn,op�ScVVnjVgV_Y[iVZUVgVeX_[Z[X\RWfXeUXWX{dR\g_ZRZ[{R�eUd XaReXf[\V\Z_Vg[fV\ZaR\iXgdZURZ[_WXYRZVgRZZUV

Page 4: Open Research Online › 56400 › 1 › The Hypanis Valles delta_ The last... · Open Research Online The Open University’s repository of research publications and other research

��������� ���� ���������������������������������������������

��� ����������������� ���������!�"#$�!%&"�%'$!�("(#)!$�$(�'!'�%�")%*'("%))$#+�*�+�!&#(����$("�)")%*���&&*%(#()����'*)��#(�%(%*+ ���'

,-./012345/6-78/95:/31,6/345/9;<=>43=4?45549@ABBCDBEFGDDAHDIE JJKLMNOPQRSTU VWQLXMYZ[WQPS\W]]MSPQQTNLXMNQ MNNW_PabcdeWfTWgXPWQhWaMiSRNUWgM_WQWjWMLW]be iPhJkcldWimWgMQLLTLXMgXTLTOZ nopqrTRQiWNZ_YWRrMN JkkstMLW]be uMULTQhfWSXMLW]be dbXM TQMUWQPS TUOWQZNMaPTQW]SMiPOMQLWNZUWQSePQLMN[NMLMiLTrMiM]LWSWQi UWQSW]]RvPW] _wP WQiYZQMje txgXP]]M JkckYWRrMNMLW]beJkksdeUTRQiLXNTRaXTRLLXM rRLVWQLXM NMaPTQeMNNW LXPSMyWO[]MPSrTLX OTNM LXWQ]WNaMNWQi gTO[]My TLXMNUWQh]PjMiM[TSPLPTQW]UMWLRNMSPQLXM WSSTgPWLMi g]TSMiNMaPTQezXPgXWNMaMQMNW]]Z zPLXPO[WgLgNWLMNrWSPQSb{MUTgRSTQiMLWP]Mi[]WQUTNO TrSMNvWLPTQSTU WNgXPLMgLRNMSMiPOMQLWNZ PQTNrPLW]POWaMNZWQiiPaPLW]M]MvWhLPTQOTiM]Sb|MaPTQW]SLNWLPaNW[XZeLXMNOW][NT[MNLPMSWQiURNLXMNXZ[TLXMSMS My[]TNMiUTNLXMUWQ}SUTNOWLPTQWNM rZxi]MNMLW]b_ dJkc~b{MSXTzLXWLW[WNSPOTQPTRSMy[]WQWLPTQUTNjMZOTN[XTh]TaPggXWNWgLMNPSLPgSTULXMSMiPOMQLUWQPSLXNTRaXiM[TSPLPTQWSW WSMNPMSTUiM]LWPgSMiPOMQLWNZ]TrMSPQ SLWQiPQarTiZTUzWLMNeWST[[TSMi �RvPW]LTiM[TSPLPTQPQW UWQSMLLPQa_�R[LWecssKdb{MWNaRMLXWLLXMUWQ]PjM]ZNM[NMSMQLSWQ WQiQTzWQgPMQLMyXROMiePQvMNLMieiM]LWiM[TSPLeWQigTQSPiMNLXMPO[]PgWLPTQSTU PQLMNhLXPS[NMLWLPTQUTNLXMMyPSLMQgMTUW]WNaMSLWQiPQarTiZTUzWLMNPQLXM�XNZSMrWSPQ LXM fTWgXPWQPQ ]WLM TN YMS[MNPWQbMWN]Z���������D-E-<41>�435�/3/31 �/��>3�19/>3/�4345029�{MRSMi�TQLMyL�WOMNW_�Vt��O�[PyM]e�W]PQMLW]beJkkKdeYPaX ugPMQgM|MST]RLPTQ�OWaPQa �y[MNPOMQL_YP|�u�t�J�gO�[PyM]t noo��g�zMQMLW]be dPOWaMSWQi YMNOW]��PSSPTQ�OWaPQauZSLMOiWLW_Y���ut�XNPSLMQSMQ d PQvMSLPaWLMMLW]beJkkl LT LXMOTN[XT]TaZe WNgXPLMgLRNMeSMiPOMQLWNZ WQiiM[TSPLPTQW]MQvPNTQhOMQLTULXMYZ[WQPSSMiPOMQLUWQgTO[]MyWQigWLgXOMQLNMaPTQb�rSMNvWLPTQSWQiOMWSRNMOMQLSzMNMOWiMRSPQaxNg�W[WQixNgugMQMuTULzWNMb�WSPgaMT]TaPgW]OW[[PQaRQPLSzMNMiM]PQhMWLMiPQ�ViWLWrWSMiTQLXMPNLMyLRNMWLLXMSgW]MTU�ViWLW_ YP|�u��c�ckekkkdSR[[TNLMirZTrSMNvWLPTQSUNTOY���uWQi_SMMSR[[]MOMQLWNZOWLMNPW] LXNMMhiPOMQSPTQW]UTNiMLWP]Sdb TNWQW]ZSPSezMgNMWLMi M]MvWLPTQiPaPLW] OTiM]S rTLXUNTO �VWQiYP|�u�SLMNMTTrSMNvWLPTQSPQ �QLMaNWLMi �OWaPQauTULzWNMUTNu[MgLNTOMLMNS_�u�udWQi�uTgMLuML}STULzWNMUT]]TzPQaLXMOMLXTihT]TaZ ����  TU¡PNjML noo¢b XM[TSLS[WgPQaTULXMw��SzMNM� �JkOUTN�VWQi cO UTNYP|�u�b\MNLPgW][NMgPSPTQTULXMw��SzWSgTQLNT]]MiLT�WNS�NrPLW]£WSMNx]LPOMLMN_��£xtuOPLXMLW]beJkkcd xiWLWb �Vw���TSWPgzWSOWiMrZaMThNMUMNMQgPQaLXM POWaM r]MQiPQaTNLXNTNMgLPUMi gRrMWQi W]TQa SMWOhWNWiPWQgM]PQMbTMSLPOWLM WNMWLXM[TLMQLPW] TULXMgWLgXOMQL_PabJdeWYZ[WhQPS\W]]MSiNWPQWaMQMLzTNj RSPQaOW[zWSgW]gR]WLMi LXMxNg�W[ckblu[WLPW]xQW]ZSL�xNgYZiNT}LTT]SML_�SNPeJkc�dLTiMLMNOPQMLXM LXMzWLMNSXMiWNMWWQiLTNM]WLM QMLzTNjOTN[XT]TaZWQiLPOPQa WggROR]WLPTQLTLXMUWQ]TrMSb WQi]Tz iPNMgLPTQ aNPiSzMNMgNMWLMi w�� gNMWLMiRSPQaLXM LXM��£x PQw��b�NNTNS LXWLSPQjSTN iPNMgLPTQrWSPQSzMNM¤]]Mi[NPTNLTgW]gR]WLPQa WQiWghgROR]WLPTQbXPSiNWPQWaMQMLzTNjzWSLXMQgTO[WNMiLTWOWQhRW]]ZgNMWLMiNPvMNQMLzTNjeOW[[MiTQW�VOTSWPgUTN¥RW]PLZgTQLNT]bXMxNgYZiNThiMNPvMiiNWPQWaMQMLzTNjiMvPWLMiSPaQP¤hgWQL]ZUNTO LXMOW[[MiQMLzTNjPQNMaPTQSzXMNMPO[WgLgNWLMNS[TSLhiWLM�TzWQi OWQRW]]ZzWSLXMNMUTNM MiPLMiLTNMOTvMMNNThQMTRS]ZaMQMNWLMigXWQQM]SMaOMQLSLXWL¤]]MiTNSLNMLgXMiWgNTSSLXMSM XMrWSPQSb XMWi LXMNMaPTQSTU STRLXMNQYZ[WQPSrNWQgXeWQi OMiPW]WQiLXM iPSLW]NMWgXMSe rTLXgTO[WNMzM]]PQ OMLXTiSbXM QMLzTNj iMhTvMNW]]iNWPQWaM WNMWWQiSLNMWOTNiMNPQazMNMLMNOPQMiUNTO LXMMiPLMixNgYZiNT[NTiRgLbD-D-¦9/549=2§35�45:21@XMLPOPQaTUiM[TSPLPTQTULXMYZ[WQPSSMiPOMQLUWQPS[TTN]ZgTQSLNWPQMib�RNNMQLMSLPOWLMSerWSMiTQgNWLMNgTRQLSUNTO LXM

UWQSRNUWgMe[]WgMS�RvPW]WgLPvPLZzPLXPQ �WN]ZLXMYMS[MNPWQLTxOWTQPWQM[TgXS_YWRrMNMLW]beJkc©de ]WLMNM]WLPvM]Z PQ�WNS}XPSLTNZbYTzMvMNegTQvMQLPTQW]gNWLMNgTRQL [TSSPr]ZOMLXTiSWNMRQNM]PWr]MeaPvMQLXMSOW]]WNMW]MyLMQLTULXMiM[TSPLSWQiiRMLT[TSLhUTNOWLPTQW]NMSRNUWgPQaUWQLXWLPSMvPiMQLrZLXMPQvMNLMiOTN[XT]TaZ_Mbabe{WNQMNMLW]beJkc�db�QSLMWiezMRLP]PMLzTOMLXTiSLTgTQSLNWPQNM]WLPvMWaM�_cdNM]WLPvMSR[MN[TSPLPTQTULXMYZ[WQPSvW]]MZSZSLMOrZW PO[WgL]WNaMeKkhjOiPWOMLMN gNWLMNeWQi_Jd gNWLMNrRUUMNMi gTRQLSb XM KkhjOhiPWOMLMNMmMgLWTUWRQQWOMigNWLMNe_PabJdezWSUTRQiLTUR]]ZSR[MN[TSMrTLXLXMSTRLXMNQ LXPSWQi LNPrRLWNZrNWQgXMSbMWSLMNQ TN gNWLMNeW]]SR[MNh[TSPQagNWLMNSªcjO PQiPWOMLMNzMNMgTRQLMizPLXPQWJKjOzPiMWQQR]RSLXWLMyLMQiSUNTOLXMgNWLMNNPOb{PLXPQLXMWQQR]RSeLXMMmMgLWPSLXPgj gNWLMNSMQTRaXLXWLW]]cjO iPWOMLMN WNMSRh[MN[TSPQabXMgTRQLSzMNMgTO[WNMiWaWPQSLLXM[NTiRgLPTQWQigXNTQT]TaZURQgLPTQSTUYWNLOWQQ_ dJkk� WQi�PgXWM]_ dJkc©WSzM]]WSLXWL �vWQTvMLW]b_ dTU Jkkcb�QLXMSMgTQigWSMeLXM�NWLMNLTT]S�rRUUMNMigNWLMNgTRQLPQa}MyhLMQSPTQzWSRSMiLTgTRQLgNWLMNSzPLXiPWOMLMNSª�kkO LXWLSR[MN[TSM YZ[WQPSLXM gXWQQM]QMLzTNj_¡QMPSS] W]beML Jkc�db�QLXM OMLXTirRUUMNMigTRQLPQa _WSSMLL YMWieWQi Jkk~deiMvM]hT[MiLT[NTvPiMWaMMSLPOWLMSUTN]PQMWNUMWLRNMSeLXMSPMTULXMWNMW iM[MQiMQL gNWLMNrRUUMNPS TQ TULXMiPWOMLMN LXM LXWLSRh[MN[TSMSLXMgXWQQM]bxRQP¥RMrRUUMNPSW[[]PMiLTMvMNZgNWLMNPQ PSLXM LXMgTRQLWQi gNWLMNUNM¥RMQgZ gW]gR]WLMiUTNMWgXPQiPhvPiRW]gNWLMNSM[WNWLM]Zb{MW[[]ZrTLXLXM LXNMMTQMNWiPRSWQiNWiPPrRUUMNOMLXTiSLTiMLMNOPQM gTRQL XMTQMLXM WNMWb NWiPRSOMLXTi kb� LXMNMUMNSLTWrRUUMNSPMLXWLPS LPOMS iPWOMLMNTULXM PQLMQiMi LXTSMgTRQLMigNWLMNWQiPS LTPQg]RiMTQ]Z gNWLMNSzXTSMNPOSSR[MN[TSMLXM LXNMM OMLXTigXWQQM]bXM NWiPP aMQMNhWLMSWrRUUMNLXWLPScb�LPOMSLXMiPWOMLMNTULXMgNWLMNb�QLXPSgWSMeW]]gNWLMNS SR[MN[TSMzXTSM r]WQjMLSMmMgLW LXMgXWQQM]WNMPQg]RiMibXMiWLWzMNMLXMQgTO[WNMiLT[Rr]PSXMi[NTiRgLPTQWQigXNTQT]TaZURQgLPTQSb«�¬­��®°�±�²�°²�±²��®³®��°�±�²-E-µ:4 ¶/664@·;�/3>@ =/5=:�435XM OR]LP[]MM¥RWLTNPW]VWQLXM TUMNNWNMaPTQ �WNSMyXPrPLS�RvPW]SZSLMOSLXWLWNMPQgPSMiPQLT]WLMfTWgXPWQhWaMXPaX]WQiLMNNWPQWQi UWQSeSTRNgMSMiPOMQLWNZ PQg]RiPQaLXMYZ[WQPSWQiuWrNPQW\W]]MS \W]]MSUWQSbYZ[WQPS PSWrMiNTgjhMNTiMiLNRQjvW]h]MZLXWLiMrTRgXMSPQLT�XNZSM ]WQPLPWWQiUTNOSUNTOLXNMMOWmTNgTQLNPrRLPQa TUrNWQgXMSNMWgXPQaWOWyPOROTrSMNvWr]M]MQaLX�ckkkjO _PabJdbXMvW]]MZPSQWNNTz_cb�¹©jO PQzPiLXdzPLXW OSPQRTRS[]WQUTNO WQiPSPQgPSMiR[LTK� PQLTLXMfTWgXPWQrMiNTgjbXM lb�LTLW]zWLMNSXMiWNMWPS� ºck�jOJWSiMLMNhOPQMiUNTOLXMxNg�W[gWLgXOMQLOTiM]ezXPgXPQg]RiMSLXMzWhLMNSXMiSTUYZ[WQPSefWQMiP\W]]MSWQiwNP]TQ\W]]MSb�VPOWaMSNMvMW]LXWL WSLXMiTzQSLNMWO NMWgXTU gTQLPQRMSfWQMiP WSOW]]_ LNPrh��kkOdPQQMNgXWQQM]ePQgPSMiPQLTLXM�TTNTULXMSTRLXMNQRLWNZTUYZ[WQPSbXPSSRaaMSLSLXWLLXM]WNaMR[SLNMWOgWLgXOMQLTUfWQMiPOWZXWvM WQiSTRNgMizWLMN SMiPOMQLLXNTRaXYZ[WhQPSWQiTRLLTLXMYZ[WQPSUWQSZSLMOb LXWLXPSW]STPQiPgWLMSfWQMiPOWZrMWZTRQaMNSZSLMO XMgTOhNM]WLPvMLTYZ[WQPSbrPQMiYZ[WQPS�fWQMiPzWLMNSXMiPSWQTNiMNTUOWaQPLRiM]WNaMNLXWQ SMiPOMQLLXM LXMMSLPOWLMigWLgXOMQLSTU UWQSTU�rMNSzW]iMgNWLMN gNWLMN_�TRiaMMLW]be_�NzPQMLW]beJkc�de»MMNT Jkc�dWQi�W]M _Wr]M XM QMLzTNjgNWLMN cdb M]MvWLPTQiWLWWQiiNWPQWaM OW[PQiPgWLMSLXWLTvMN]WQi SZSLMO�TzTULXMYZ[WQPS¹fWQMiP TNPaPhQWLMiUNTO LXMXPaX]WQiSLXWLSRNNTRQi LXM�WNOPgXM]gNWLMNWQiNMaPTQzMSLTU�NSTQ{M]]MSgNWLMNb XMNMPSQTTrvPTRSaMQMLPggTQQMgLPTQrMLzMMQLXMYZ[WQPS¹fWQMiPQMLzTNjWQiLXMQMWNrZYMS[MNPWQLTMWN]Z TRL�TzxOWTQPWQhWaMgPNgROh�XNZSM gXWQQM]S_YWRrMNMLW]be tJkksfM]STQWQi �NMM]MZecsssdb

Page 5: Open Research Online › 56400 › 1 › The Hypanis Valles delta_ The last... · Open Research Online The Open University’s repository of research publications and other research

��������� ���� ���������������������������������������������

��� ����������������� ���������!�"#$�!%&"�%'$!�("(#)!$�$(�'!'�%�")%*'("%))$#+�*�+�!&#(����$("�)")%*���&&*%(#()����'*)��#(�%(%*+ +��'

,,- ./0123456718/9:1;7<153.815671;=>?@65?6A6776;BCDDEFDGHIFFCJFKG

LMNOPOQRSTUVWXTYYZW[T\[] ZU\TU_WZ_VZU\TUWRW\Z abTcdQefghUVi]\j\VZ klTU[]ZW_T\TW]mnVUi\]ZWZ_VZU\TUo bp bqTU_ TU_rco YmkZW TU_ \]Zl TYscTWYmnVUZl\VTY VUZl\VTY_ZSmWV\WbkYtZcmU m\]ZW[TYZ uvv^TiTVUW\ ]Vi]Zl\]Z \]Zl TY wStWtlT[ZblZ_cxd]ZYmnZl\]Zl TYVUZl\VTWtiiZW\W\]Z TUyWWtlT[ZVW[m SmWZ_mzUZl TU_ml SmmlYR m mU^mlZ [Z ZU\Z_ d]VWilTVUW\]TU\]ZWtllmtU_VUi^T\ZlVTYWx ^T\[]ZWmkWZl{T\VmUW Z|\ZUWV{ZTZmYVTU^T\ZlVTYW \]Z TU_ZSmWV\W}bkc~mU\Z|\ ^m_ZY[T\[] ZU\T[lmWWqTU\]ZdZllTW]mnVUia m\]ZZ|\ZU\ \]Z \]ZQRSTUVWTU_hTklVUTWZ_VZU\TUWbkYT[�c} {TYYZRUZ\nml�m QRUZ�Z\TYxb,vuvcV_ZU\VzZ_VUdQefgh_T\Tbn]V\Zc}\]Z]R_lmYmiV[TY m_ZYZ|\ZU\m \]Z[T\[] ZU\mlQRSTUVWbkYT[�YVUZcn]V[]VU[mlSmlT\ZW\]Z^m_ZY[T\[] ZU\ml�TUZ_VXTYYZW \]Zb_TW]Z_YVUZcTU_ ^m_ZYh\lT]YZlW\lZT UZ\nml�bh\lT]YZlou���} �ml_ZlW \m�}YVi]\\m_Tl�kYtZcxpYWmW]mnUTlZ^T�ml[lT\ZlW\]T\YV�ZYRSmW\_T\Z\]Z \]Z^T�mlV\Rm T[\V{V\RVU {TYYZRUZ\nml�blZ_]TW]cx

Page 6: Open Research Online › 56400 › 1 › The Hypanis Valles delta_ The last... · Open Research Online The Open University’s repository of research publications and other research

��������� ���� ���������������������������������������������

��� ����������������� ���������!�"#$�!%&"�%'$!�("(#)!$�$(�'!'�%�")%*'("%))$#+�*�+�!&#(����$("�)")%*���&&*%(#()����'*)��#(�%(%*+ %��'

,-./012345/6-78/95:/31,6/345/9;<=>43=4?45549@ABBCDBEFGDDAHDIE JJKLMNOPQRSTUVWXYSZS[\]_VYSZ`VWYab]_V cVZVW]VdeTJf gV_]WYh]\VW]VdeTJf iVYXZ_jU] kSlV_XSZmjUVZXY Kno pqrstsop uU]Z ssvwxpyvgz]{]WSV qy | sorst p uU]Zdz]{]WSlWV_]Wx\WVXZY_S}YX\XY~VZX_XVf s�vwxnnv���]WY�V\]� sJy s sornt p RSY]\d��]WY�V\]lWV_]Wf Jpv�x||vg�V�WXZVl Jyq � �Zl]VWd V�SZ�lWV_]Wf sJvwxpnvg�]W�j\ � uU]Zd_Sm]VY~VZX_XVf J�v�xnpv�V �S�\�]]_VadJosyfa� }W�XZ fa]_VadJosyl ~V_{]_ ]_ ]_ cX�aVadJospfx�ZV\] VadJosnfxmV��]W VadJos|f� sa\ �ZYVZ]_VadJossfa�-D-�:4�;�/3>@@41>�435�/3�h] eT eTmjUVZXYY]\XT]Z_[VZXYV�po �X\]VZ\�qo SZ�XZ�]W_]\Y]\XT]Z_VWj\]USYX_ S[SlV_]\ZSW_h _h]W]�XSZV�W]VeXZYSU]_hV_ �S�Z\VWj\]TVWlV_]Y_h] �]_�]]Z_h]wSVlhXVZ�V�]�VZ_h]�]WWVW]�XSZxm]YU]WXVZV�]\_WVZYX_XSZV �ZX_YVZ\_h]�TV{SZXVZ�V�] RhWjY]Y�W[Vl]S[ ~VZX_XVd�VZVeV Vax]_ JospxcX�aJ�fa _h]�hXYYhVWUW]�XSZV _WVZYX_XSZx_]WT]\ RhWjY]]Y�lVWUT]Z_xXYlhVWVl_]WXY]\�jVlhVZ�][WST_]WWVXZhSY_XZ�Z��T]WS�Yh]V�Xj\]�WV\]\XTUVl_lWV_]WY�UYSU]S[_h]]YlVWU�T]Z_dWXTYVZ\]�]l_VW]TS�]\x�SSWYXZ� ]\ _h]wSVlhXVZ\�WXZ�dRWV\\Sle]_Vax �sKKn}W�XZ]_V axJos|fx_S_h]_SUS�WVUhXlVjYTSS_h]W \S�ZYSU]x XZ� ]\UVXZY �hXlh Z�T]WS�YhSY_ ��hSY_�lWV_]WY lWV_]WYVZ\ �X_h lSZ_XZ�S�YS�V_] ]�]l_VTVW�XZYdiVWS�]_Vax �Jooo�V�V_SW]VZ\ RhWXY_]ZY]Zx Jospfa�h]_WVZYX_XSZXZ�]\WSle�]SS�j ]]�V_XSZSll�WYV__h]YVT] VY VZ\_h]mjUVZXY�V�WXZVS�_]_Y�hXlh _WVZYX_XSZY���]Y_Y_hV__h] _S\]USYX_XSZZSW_hS[_h]RhWjY]]YlVWUT]Z_ _SUS�WVUhXlVj�VYUVW_j lSZ�_WS]\a�h]mjUVZXY[VZXYl]VWj\XY_XZ��XYh]\�YXZ��m� }�ZX�h_�_XT]Y�W[Vl]_]TU]WV_�W]\V_VxXZ�hXlh_h]Y]\XT]Z_VWj[VZ�S\jYhS�Y \VWeV _SZ]XTUjXZ�VS� _h]WTVXZ]W_XVW]V_X�]_S_h]Y�WWS�Z\XZ� _]WWVXZYY�WWS�Z\XZ�TX\�_SZ]\UVXZYVZ\�WX�h_]W_h] Y���\X�X\]\_h] VYYSlXV_]\[VZdcX�aJVfag] [VZVZ\ \]USYX_YXZ_S S[_hW]] _h]TVU�ZX_Y� [VZXYlSTUWXY]\ _h]�UU]WVZ\kS�]W[VZ�ZX_Yd�[� k[��VZ\ cX�as\fx�hXY__h]�]\WSle�]SS�jS[_h]Y�WWS�Z\XZ�UVXZY UVXZYXYTVUU]\VY_h]~]WXUh]WV �ZX_d~U��cX�as\fa�h]TVXZY]\XT]Z_[VZd�[� k[�fVZ\ [SWTYVZVUUWS�X�TV_]jY]TX�lXWl�VWVWl�V_]�S\jx�X_hY]�]WV�V_�_SUU]\WX\�]Y�WVZlhXZ�S[[VZ\]�_]Z\XZ�spoeT_S_h]ZSW_h�]VY_dcX�as\fa�h] _h]Y]]]�V_XSZS[ \]USYX_Y\]Yl]Z\Y [WSTyooT �JpnyTV__h]mjUVZXY V]YS�_]__S��|oooT [SW_h]TSY_ZSW_h]WjTVUU]\ �ZX_S�_lWSUYdcX�as\fa�h]~]WXUh]WVUVXZY d~U�flSZ�YXY_YS[\VWe_SZ]\ S� W]X][TV_]WXV �X_hZ�T]WS�Y\VWe]WYTSS_hUV_lh]Y_hV_]�_]Z\V�Vj[WST_h] _h]TVW�XZYS[ Y]\�XT]Z_[VZa�h]�ZX_VUU]VWY_SW]_VXZYTV d¡oayeTflWV_]WYhS�]�]W hV�]_h]Y] \]�WV\]\SW WXTY S[_]ZZS VZ\ hV�]Vj]WYS[ _h]TTV_]WXVXZYX\] dcX�ap\fagh]W]_h] _h]�ZX_VUUWSVlh]YTVXZ ]�hX�X_XZ�[VZX_hVYVYTSS_h]W_]�_�W] USj�SZV[WVl_�W]UV__]WZYdcX�ay�fau�_X]WYS[ Sll�WSZ S[~U�TV_]WXV _SU _h]Y_WV_VS[ dcX�Ya SZ_h]TVXZ[VZ |�xyVfVZ\ VmX¢}��YlV]_hXY�ZX_XYl]VWjY_WV_X�WVUhXlVjXZ_]W�]\\]\ S[�X_h_h]TVW�XZY_h] lfaY]\XT]Z_[VZdcX�ap �WVl]\�]Y_�VW\Yx_hXYTV_]WXVSZVUY_h]\]�WV\]\S�_]W lWV_]WxWXT S[ V�SZ� VUUWS�XTV_]j[SS��XZ�_h]�JyooT `uk�lSZ_S�Wa l�Y_]W�S_h]]VY_xV S[WS�Z\]\��__]Y �ZX_aVUU]VW_SS�]WX]_h] �h]UW]Y]Z_ Y�W[Vl]\Vj ]WS\]\XZ_S YSU]Y_h]~U� _S_h]ZSW_hxVZ\XY_SUS�WVUhXlVjSU]Z_SRhWjY]~VZX_XV S[VZ\VW]S�]WVXZ�jTV_]WXV _h]]VWjm]YU]�WXVZ_WVZYX_XSZ�ZX_d]m_fXZ_h]�S�VY_WV_X�WVUhjS[�VZVeV]_Vad fJospa

�-�-,92£>�/6�;�/3>@@41>�435�/3¤21;�h]UWS�XTV \]USYX_mjUVZXYY]\XT]Z_[VZ lS�]WYVZVW]VS[�KnoeTJVZ\ VZ VWl[SWTY XWW]��VWJyeT�WV\X�YY]TX�lXWl�VW_hV_WV\XV_]Y[WST _h]S�_]_  V]YS[mjUVZXY dcX�a|Vfa�ZVj�YXYS[_h][VZXZR��VZ\mX¢}��\V_VYhS� _hV__h][VZ�S\jXYlSTUWXY]\S[Y]�]WV lSTU]�XZ_]WVj]W]\Y]\XT]Z_VWj\]USYX_YdcX�Ya|�xfapw�T]WS�YS�Y]W�V_XSZYS[ Vj]WXZ�VZ\Y_]]UYlVWUYY���]Y__hV_TSY_xU]WhVUYVxS[ S[lSTU]_]Z__h][VZ�S\jXY[SWT]\Y]\XT]Z_VWjWSlea�h]�UU]WVZ\kS�]W[VZ�ZX_Yd�[�VZ\k[�fxVW] VZ\lhVWVl_]WXY]\�j\X[[]W]Z_Y�W[Vl]_]�_�W]Y ]�h�TV_XSZ ]��]YdcX�as\fa�h]�UU]W[VZ�ZX_S�_lWSUYXZ_h]YS�_h]WZUVW_S[_h] _h][VZx �UU]W Sll�WYY�W[Vl]S[�hXlh V_VhX�h]W]]�V_XSZ_hVZ_h] _h]�[�kS�]W[VZ�ZX_a�hXY Y�W[Vl]�UU]W]�h�T]\ S[�ZX_d\VWe��]xcX�as\fYhS�YV\]ZY]Z]_�SWeS[lWSYYl�__XZ�xY_WVX�h_ W]X][_Sl�W�XZ�XZ]V_XSZY_hV_YST]_XT]Y[SWT S� WX\�]YdcX�Yalx S[ UWS�XTV| pVfa}Z_h]�]Y_]WZUVW_ _h] [VZx_h]XZ]V_XSZYVW]SWX]Z_V_]\VUUWS�XTV_]jw��dcX�Ya|VxVfap }Z _h]lSZ_WVY_xXZ]VY_]WZUVW_S[_h] _h][VZx XZ]V_XSZYVW]SWX]Z_V_]\��ga�h]XZ]V_XSZY ]SZ�V_]SlVjVUU]VW_S\]�Z] so�sooT��X\]�lSWWX�\SWY�_hV_lWSYY�l�_SZ]VZS_h]WdcX�apVfa�h]XZ_]WZVY_WV_X�WVUhjS[_h]�UU]W XY[VZ�ZX_ ]�USY]\ ]WSYXSZV YlVWUVSZ�VZ _hV_\]�Z]Y YlVWUX_YZSW_h]WZTVUU]\ �hXY hX�h]�_]Z_a �Jo�|oT ]��USY]YlSZ_X��S�YxT]_]W�YlV]xY���hSWX{SZ_V Vj]WXZ�_hV_lSZ�WT_h] _h]UW]Y]Zl] �X_hXZS[Y_WV_X�lV_XSZ [VZdcX�Ya|�xVfap�h]kS�]W[VZ�ZX_ TVUU]\Y�W[Vl]hVYV VW]VS[�JyoeTJVZ\XY �UU]W]�USY]\_S_h] _h]ZSW_hS[ [VZ�ZX_a�h]�UU]WY�W�[Vl]S[_hXYY_WV_V�ZX_YhS�YV��Z\VZ_wg����_W]Z\XZ�WXUU]�Xe][]V_�W]YeZS�ZVY�WVZY�]WY]�]SXVZ¢X\�]Yd��¢Y�]a�axiVT]]_VaxJoo��cX�a|�famS�]�]Wx�VUYXZ��¢lS�]WV�]YhS�_hV__h]k[�XYlSTUWXY]\S[X�h__SZ]\xYTSS_h�_]�_�W]\Y]\XT]Z_VWjTV�_]WXV�X_hSllVYXSZV S��W]X][T]YVY _hV_VZ\USj�SZV[WVl_�W]YS[_]ZSll�W dcX�YaXZYhVS��V_��S__ST]\UX_Y pVxy�fa��_]Z\XZ�sooeT ZSW_h[WST TVXZY]\XT]Z_�S\jXY_h]�X\]YUW]V\~]WXUh]WV UVXZY�ZX_d~U�fa�hXY�ZX_hVYV�VWX]_jS[Y�W[Vl] mjUVZXY_]�_�W]YVZ\hVYVlSTU]�W]V_XSZYhXU�X_h_h]Y]\XT]Z_ V\�Vl]Z_hX�hVZ\Ya�S\X]YVZ\_h] �h]�UU]W[VZ�ZX_�]Z]WVjSll�WYV_VhX�h]W]]�V_XSZ_hVZ_h]~U�VZ\XYS[_]ZY]UVWV_]\ ]WSYXSZVYlVWU[WST_h]~U��jVZ VZ\k[�x]�l]U_YS�_hS[ \]UW]YYXSZSZ S[_h]TVXZ[VZxVZ\XZV _h]�]Y_]WZTVW�XZ _h]TVXZ[VZ [VZdcX�Yaq pVVZ\ \fa�h]kS�]W �ZX_dk[�f�]Z]WVjS�]W�X]Y_h]~U�x_hS��h_h]�S�Z\VWjYST]_XT]YVUU]VWY�WV\V_XSZVxVZ\_h]lSZ_Vl_ TVZjXY XZS�Yl�W]\SWVT�X��S�Y UVl]YdcX�Yay�xqlfa _h] _h]�\�Vl]Z__S Y]\XT]Z_[VZx ~U�YhS�YVYTSS_hY�W[Vl]lhVWVl_]WXY]\ _WVl]\�jUSj�SZV[WVl_�W]Y ��_dcX�Yapyxfx [�W_h]W[WST_h] _h]Y]\XT]Z_[VZ Y�W[Vl]XYWSleX]WVZ\VUU]VWY_SW]_VXZZ�T]WS�Y lWV_]WYaYTV w�T]WS�Y\VWeUV_lh]YxlSTTSZjVYYS�lXV_]\�X_hY��_]_SUS�WVUhXlS�Y �xVW]S�Y]W�]\dcX�Yaq nlfa�h]�UU]WVZ\kS�]W[VZ�ZX_YlSTUWXY] S�V_]�S\X]Y_hV_UWS_W�\]ZSW_h�VW\YXZ_S ~VZX_XV_h]RhWjY] �VYXZa�h]ZSW_h]WZTVW�XZS[ XWW]��VW_h]�UU]W XY[VZ�ZX_ hX�hj [SWTXZ�\XY_XZl_�Z�]W�Xe] _h]Y]UWS�]l_XSZYdcX�a|Vfx�hXlhY���]Y_Y_hV_ TVjW]U�

Page 7: Open Research Online › 56400 › 1 › The Hypanis Valles delta_ The last... · Open Research Online The Open University’s repository of research publications and other research

��������� ���� ���������������������������������������������

��� ����������������� ���������!�"#$�!%&"�%'$!�("(#)!$�$(�'!'�%�")%*'("%))$#+�*�+�!&#(����$("�)")%*���&&*%(#()����'*)��#(�%(%*+ $��'

,-. /012345678290:;2<8=264/926782<>?@A76@7B7887<CDEEFGEHIJGGDKGLH

MNOPQPRSTUVW XWYZ[\SX[]\ UVW [YW_X[]\ [\WTa [YYWbcSYdY]e[ZSfW[ZW\XgS\SXXVW ]g fV]h[\bijkdS\[flSWf gY]ZXVW]cXWXRmcW XVW WY]f[]\Sf_SYdmWXhWW\XVWcddWYRngcTS\ fcYgS_Wf ZSXWY[S omYS[WpSXX[_Wq]hWYRrgcTgS\ R]XXW XVW[\WTabYSSX[]\Sm]c\SYkmWXhWW\ rgcS\ dS[\fsWY[dVWYS Rsdca SfVW [\WTa]htYW[Wg [\WSX[]\f]\ ]gXVWcddWYfcYgS_W XVWZS[\ Rr[TagS\ Y[mm]\t[uWY[bWffV]h[\bmSf[\hSY Y]cX[\b]gfW[ZW\XRvYTaSXWtfXSbW[\_[fW _VS\\WfRSfVW mcWSYY]hfTaY]c\ W mcXXWf]gYWZ\S\X]wWYmcYW\RhV[XW ZSXWY[S x\bWYt[uWc\[XTasWY[dVWYS dS[\f RsdcTyRmTz dY]{W_X[]\ hV[_VgY]Z XVWZS[\gS\fV]h[\bSkWYf _S\mWXYS_W g]YXW\f]guZfS\]cX[WYf Y[bWy XYW\[\b]g ]\ ]gsdc X]d XVW |}t~� Uzvf_S\Sf]mWfWW\y

Page 8: Open Research Online › 56400 › 1 › The Hypanis Valles delta_ The last... · Open Research Online The Open University’s repository of research publications and other research

��������� ���� ���������������������������������������������

��� ����������������� ���������!�"#$�!%&"�%'$!�("(#)!$�$(�'!'�%�")%*'("%))$#+�*�+�!&#(����$("�)")%*���&&*%(#()����'*)��#(�%(%*+ '��'

,-./012345/6-78/95:/31,6/345/9;<=>43=4?45549@ABBCDBEFGDDAHDIE JKL

MNOPQPRSTUVWXSYWZ[\]S\_ZS[]ZSaV[bZWXS[c\_V[a_cdVWeS[\dS\f_Vcg[\][\WZXSbW _ZS[]VcbhZi[\]fLjkLjjeg[WfXcgZWX[WdZ[]W_Rl[mnXhWSZZcgWX[\W_TopqSeaXW_ raaWZ h\[cdXSYWZ[\]Wqac_W[\ VWJjkKje V[]V_bSZaS VW ZS\_[[c\nWgWW\ VW S\ lcgWZdS\ gV[bV ZS\_[[c\_[\c VWacXY]c\SXXYdZSbhZW aSZ_cdVW VW VW [\sXXW VWtahouX_c_WW\SZWWqSeaXW_cd tah aSZ_ciWZXY[\] [_SX cd dS\S\ bZSWZS]Vc_ RS_VW X[\WTVS [_ nYS_ahZcddS\eSWZ[SXdZce eS[\dS\ovcVVW VWdS\S\ aXS[\_ SZWh\[ ciWZXS[\nY Zch\ W SX_cnh W_ SZWRwnToUVW_WZWXS[c\_V[a_ _Vcg\[\ S\RnT RbTcac]ZSaV[b SSx[wyzp[eS]Wpzt{jK|}~L{L�JjR�U� |f_WW [\dcZeS[c\T S_VW_T_haaXWeW\SZY gVWZW eSWZ[SXWXWeW\_ VWcd dS\ RncV gV[W_hn�s]hZW_fXSYWZ_� SZWciWZXS[\nYfS\ ciWZX[WfeSWZ[SXS__cb[SW g[V VWtahRncV_hn�s]hZW_fnch\SZY� Zch\ WnXSb� c W X[\WTovcV h\WZX[Wh\[_ VW nh W_RwnTo

Page 9: Open Research Online › 56400 › 1 › The Hypanis Valles delta_ The last... · Open Research Online The Open University’s repository of research publications and other research

��������� ���� ���������������������������������������������

��� ����������������� ���������!�"#$�!%&"�%'$!�("(#)!$�$(�'!'�%�")%*'("%))$#+�*�+�!&#(����$("�)")%*���&&*%(#()����'*)��#(�%(%*+ ���'

,-, ./0123456718/9:1;7<153.815671;=>?@65?6A6776;BCDDEFDGHIFFCJFKG

LMNOPOQRSTUVW TUVWXYZ[W\]W_ZW aW\bW]ZcRZ[dReR] XUW_aZWcc\]f R]Z[W Z[WWgZW]ZUh iccW_ TUdW_ U]hR]aZ_RZRjk]\ZaQRa[W j\]WaSlmkVZjWj\]WRZ\U]aR_W \a\VjWZ[W Z[W h_RnZk_W Z[WkccW_ak_hRnW QVSUhZ[\ajUVWl oWZR\jh_Ub \]W_ZW aW\bW]ZcRZ[dRe\]p\qrmssmtuv-w-xwuyx,va[Ud\]fZ[W R_z tck{jReW_ad\Z[\] _\fWR] |}qaRaaUn\RZW tckd\Z[ j\]WRZ\U]a QT\SZ[WhR]k]\ZalQnS|[Wak_hRnW a[Ud\]fUhTUVWX U]Z[Wak_hRnW R] R_zUkZj\W_aUh bRZW_\Rj \]UW_je\]fTUVWX p\qrmssmtuv-w-xwuyx,vos~ akccjWbW]ZR_e\]hU_bRZ\U]SlxQaWW_WaW]ZR]W_Ua\U]Rj_Wb]R]ZUhhU_bW_jebU_WWgZW]a\W WcUa\ZaZ[RZ[RWVWW]W_UWVeaUkZ[dR_anR_c_WZ_WRZ{WgcUa\]fk]�W_je\]faZ_RZRUhZ[WTUdW_hR]k]\Z k_\]fZ[\ac_UnWaal�\jUbWZ_WanRjW R] Rn_Uaa[\jja VkZZWaUnnk_ Z[W Z[W]U_Z[W_]UkZn_UcaUhaW\bW]ZVUeR]Rn_UaaZ[Wak__Uk]\]fcjR\]aQ�\fal,-{R{wSl�jUaWWgRb\]RZ\U] \]\nRZWaUhZ[WaWhWRZk_Wa Z[RZZ[WeakcW_cUaWZ[WhR] WcUa\Za{_RZ[W_Z[R]c_UZ_k\]fZ[_Ukf[h_Ub VW]WRZ[Z[Wbl|[WeR_WZ[W_WhU_Wj\zWjeW_Ua\U]Rj_Wb]R]ZaUhR]UjW_{R]c_W\UkajebU_WWgZW]a\W{UW_Vk_W] WcUa\ZZ[RZU]nWak�cW_cUaWZ[WaW\bW]ZhR]R] Z[Wd\W_R_WRl�W\]ZW_c_WZZ[Wj\]WRZ\U]aR]_\fWaUhZ[WiccW_hR]k]\ZQ�\fl-SRaZ[W\]ZW_aWnZ\U]UhbkjZ\cjWn[R]]WjRnn_WZ\U] WcUa\Zad\Z[ c_WaW]Z�ReZ[W ak_hRnWlr]ZW_WaZ\]fje{dW U]UZ R]eUVaW_Wa\]kUka n_UaankZZ\]fn[R]]WjhU_bal|[W_\fWaRccWR_ U_V_R\WU] Uh UhRjW]fZ[anRjW ZW]a bWZW_aR] akV�ZW_b\]RZW\]abRjjaWb\n\_nkjR_hR]�j\zWR__R]fWbW]ZaQ�\fl-nSl}njWR_WgRbcjWUhZ[W Z[W Z[W_WjRZ\U]a[\cVWZdWW] iccW_hR]k]\ZR] k]W_je\]fZUcUf_Rc[e\aUVaW_W U]Z[WdWaZW_]bR_f\]d[W_WhR]akcW_�cUaWd[RZ\a]UdRf[UaZn_RZW_Q�\flwRS{Z[W_WVe WbU]aZ_RZ\]fZ[Wc_WaW]nWUhR]k]nU]hU_b\ZeVWZdWW]k]W_je\]fbRZW_\RjaR]hR] WcUa\Zal�/K/ ��<15568�84�6�43=�[R]]Wj�jUVWVUeX S RQ�\fal{y� nUbc_\aWa _\VVU]�hU_b aW\�bW]Z ����VUeQ�kWRa ,vyv�~R_Z�]W�WZRjl{ �\Vj\]fR] qkaZ{ S{R]R__Ud{ VUe Z[RZWjU]fRZWaW\bW]Z d\Z[RakV�a\]kUkacjR]hU_b{[Ra VUeRZRjUVW�a[RcWaW\bW]ZR_e \ZaZW_b\]kal|[W_\VVU]�VUe\]\Z\RZWad\Z[\]c_Ug\bRj Z[W]hR]aZ_RZRR] WgZW]a]U_Z[�dR_VWeU] \Za]U_Z[W_]bR_f\]l�U_Z[UhZ[WpecR]\a�RjjWaUkZ�jWZ{\ZhU_baR�,zb d\WR] �y-zb jU]f�RZ�ZUccW _\VVU]�hU_b VUel|[WbR_f\]aZ[\ahWRZk_Wa[UdaZ[RZ\Z\anUbc_\aW

\]ZW_]RjjeUhy��bZ[\nzjReW_a\]p\qrms\bRfWaakffWaZ\]fRaW�\bW]ZR_eU_\f\]Q�\fl�VSl�WeU]Z[Wc_Ug\bRjhR] WcUa\Za{Z[\ahWRZk_WhU_baR��v�b�ZRjj_\fW\]Z[Wnk__W]ZjR]anRcWQ�\fal,V{- �R{SlpW_WZ[W_\VVU]�hU_b VUea[Uda bR_�aZWWc{nj\hh�hU_b\]ff\]aR]UW_j\WaZ[WtW_\c[W_RjcjR\]ak]\Zl}ZZ[WnU]ZRnZd\Z[Z[W h_Ub Z[WtW_\c[W_RjcjR\]a Z_R]a\Z\U]k]\Z{Rf_RRZ\U]Rj jRe�W_W _\fWZUabUUZ[h_RnZk_W bRZW_\Rj\aUVaW_W{d[\n[a[UdaZ_R]a\Z\U]\]ZUbU_W h_RnZk_W{_kffW{VkZaZ\jj ak_hRnWaQ�\fl�V{nSl}cc_Ug\bRZWje�vzb ]U_Z[UhZ[WpecR]\a�RjjWaUkZjWZZ[W_\VVU]VUe VUeWgcR]aZUhU_b RjUVRZWaW\bW]ZR_e_Unz Z[RZ\a \a�yv y- Slzbd\WR] zb jU]fQ�\fl� ~WZ_W�anRjWjReW_\]fUVaW_W \]aWnZ\U]aRZZ[WbR_f\]aUhZ[\aVUel|[\ajUVRZWVUe[RaRnU]Wg�kcn_Uaa�c_U�jW bRg\bkbR] [RaR Z[\nz]WaaUh���bl}Z\Za]U_Z[W_]bR_f\]{\ZZRcW_aUkZR]a[UdaRV_kcZZ_R]a\Z\U] cjR\]a nU]�\]ZUZ[WtW_\c[W_Rj k]\Zl|[W]RZk_WUhZ[\aZRnZ\ak]njWR_\]U_V\ZRj\bRfWal|[WkccW_ak_hRnWUhZ[WjUVRZWVUe\anUW_W\] nk_�RVk]R]Z|}qa{VkZaZ_R\f[ZZUaj\f[Zje\]fj\]WRZ\U]aQ�\fal �-{RSnR]VWUVaW_W Z[_Ukf[Z[WjUUaWnUW_RaaUn\RZW d\Z[|}qaQ�\fl�RSl|[WaWj\]WRZ\U]aRccWR_ZU_R\RZWRdReh_UbZ[WRcWgUh _\VVU]�j\zW_\fWZ[W Z[RZnU]]WnZaZU\ZTUVWXZUZ[WbR\]hR]l�W\]ZW_c_WZZ[W_\VVU]�jUVWaW\bW]ZVUeZUhU_b Ra\]fjWnU]]WnZW aW\bW]Z_UkZ\]faeaZWb W_\W h_UbZ[WpecR]\aUkZ�jWZl|[W_\VVU]VUe\a\]ZW_c_WZW RaZ[W]Ud\]W_ZW hU_b UhR�k\Rjn[R]]WjVWjZQ�kWRa~R_Z�]W�WZRjl{,vyv r] aUkZ[�Sl \ZaW_]_WRn[{Z[Wn[R]]Wj WcUa\ZaR_WWjWRZW Ve�,�b RVUWZ[W\aZRj Z[W Z[WcR_ZaUh c_Ug\bRjhR] WcUa\Za\] p\qrmso|~QaWWakccjWbW]ZR_e aZ_RZ\f_Rc[\nRjjebRZW_\RjS{\]\nRZ\]fZ[RZZ[WeUW_j\W{R] R_WZ[W_WhU_WeUk]fW_Z[R]{ bUaZZ[W UhZ[Wc_Ug\�bRjhR]l�U_Z[dR_ VWeU] Z[W Z[Wn[R]]WjhR]{ aZWcaUkZRn_UaacjR\]abRZW_\Rj\]\nRZ\]fZ[RZ\ZUW_aZWcaZ[W Z[WWfWUh hR]l

Page 10: Open Research Online › 56400 › 1 › The Hypanis Valles delta_ The last... · Open Research Online The Open University’s repository of research publications and other research

��������� ���� ���������������������������������������������

��� ����������������� ���������!�"#$�!%&"�%'$!�("(#)!$�$(�'!'�%�")%*'("%))$#+�*�+�!&#(����$("�)")%*���&&*%(#()����'*)��#(�%(%*+ !��'

,-./012345/6-78/95:/31,6/345/9;<=>43=4?45549@ABBCDBEFGDDAHDIE JKK

LMNOPOQRSTUVWX YVWZ[\VW] _STXXWabWT\[STXX\WbcdSe fZg\VWRTQRSTUVXWabWT\hZa XVZiT T STa dhjgWSXXZUS\ZTi\V _jSTXkWR_VWRSj dk_ge \VW Zg\jW\] _STXSRRZieliVUVX jS\WmX\SnW dhjgWSXXZUS\Wai\V WRZXZTSjUVSTTWjX aSXVWaSRRZie XWabWT\ QRSTUV RZgTaWaUg\\Tn\VZgnV\VW [STcYVWfZg\VWRT XZoWRjSTh hg\\WXdphe Z[STa Xb_SU\ dheWqWU\S\Z\VWWSX\c QRSTUVr [ZRbWa UgRojTWSRlT\WRjSUWahRSTUVTn ToWR\WaUVSTTWjXWnbWT\XlZoWRjSTh RZgTaWahg\\WX STadphe\Z\VWTZR\VXgRRZgTaWa k_gh i\VXbZZ\V_S\UVWXdf_ecQRSTUV XWabWT\Q SXVZiX hZa i\VjZiRWjW[RanWX dUe\VXWs_ZXWadtecuTaW\Sj XWabWT\hZa XVZiXXWoWRSjX\RS\STUjgaTnS SXgR[SUWi\VvmwjTWS\ZTXdtlhjgWSRRZiWajTWXeT]pufwkfkxyzy{z|xz}Jy~w� zydXWWXg__jWbWT\SR bS\WRSjeSTa XghqSUWT\XgR[SUWi\VjZiRWjW[jTWS\ZTXdte XWWT\RWTaTn�wcrnSTljSWRTnX T dpanW STa \\VW daeX\WW_RanW�ST�Xc YVW RanW \iTmRanWXgR[SUWZ[ r SXVZiX UZb_jWs XX\Wb rz rJe\VS\XgnnWX\XXbSaW panWZ[XWoWRSja[[WRWT\X\RS\SjgT\Xc r S gT\XVZiX nRSaS\ZTSjhZgTaSR i\V\VWkWR_VWRSj_jSTX dk_gec

Page 11: Open Research Online › 56400 › 1 › The Hypanis Valles delta_ The last... · Open Research Online The Open University’s repository of research publications and other research

��������� ���� ���������������������������������������������

��� ����������������� ���������!�"#$�!%&"�%'$!�("(#)!$�$(�'!'�%�")%*'("%))$#+�*�+�!&#(����$("�)")%*���&&*%(#()����'*)��#(�%(%*+ ����'

,-. /012345678290:;2<8=264/926782<>?@A76@7B7887<CDEEFGEHIJGGDKGLH

MNOPQPRSTU SVWXYZW[\]S[Y[ _S\_a_bcSadY _efYgWhibd_V\cS\WcjS\kl,mnnZ _] _] bd_V\Vd_eVRYT\dWW[X ocS[dUfc_VVY[b\dWcYZ \dW cS\WcRedY\W_[bpXSVdWXY[WT\WcZY[S\Y[bY[VWXYZW[\]S[q_rWsRSaac_tYZS\WZScbY[VVd_e[rhVd_c\XSVdWVTuvdWWXbWV_]\dWVWXYZW[\]S[ c_a_w\]c_Z \dWZS[\Y[b_]YZaS\WxW\SRyTuvdWVWXYZW[\]S[_ wcV SY[ \_a_bcSadY_ef_[\_wcVScW S\Vd_e[XWVW[XY[b Z Z]c_Z l,z{| RYbd\WV\rwWT\_l,m{| RXScgWV\rwWTfYcwZVcYrWX \dWcYZ \dW_] bd_V\cS\Wc rw\\WVrhc_w[XWX R}rTuRrTy_ZWShWcY[bYV Y[VWW[ \dWWXbW_]\dW]S[edWcWY\Wta_VWXu~_eW�Wcf\dYV \dS[ScWSYV Wc_XWXVYb[Y�S[\h WVV \dWZSY[]S[S[XYVZS[\WXrhYZaS\ w[XWchY[bWxW\SV_SaaWScVZ_cWZSVVY�WuRT�S\\_aaWXrcYbd\cYXbWVWbZW[\V c_w[XWXrw\\WVR}rTuvdWcYXbWVWbZW[\VSaaWSc XYV\S\_rW cWZ[S[\V_]Y[�Wc\WX dS[[WVVW\Y[VZ__\daSc\V R�awTuRyZT_]\dW�WcYadWcSaSY[V

Page 12: Open Research Online › 56400 › 1 › The Hypanis Valles delta_ The last... · Open Research Online The Open University’s repository of research publications and other research

��������� ���� ���������������������������������������������

��� ����������������� ���������!�"#$�!%&"�%'$!�("(#)!$�$(�'!'�%�")%*'("%))$#+�*�+�!&#(����$("�)")%*���&&*%(#()����'*)��#(�%(%*+ ����'

,-./012345/6-78/95:/31,6/345/9;<=>43=4?45549@ABBCDBEFGDDAHDIE JKLMNOPQRSTO UOVWXRQVYWUSVWUTWZ[T\OST]O\Q_OVRYVOQUWTWQZQ\_OZTSTTNOTO_WZ]UQ\S\OOVO[NSZZOPTNSTNSUWTUOP\RO[Q_OUOVW_OZTXWZaPPOVb \Q_MNO PWZOS`OUOZ[OQ\ \OST]OU SVWSTWZcTNO TNOSOdQ\ WRRQZRQVY SOU]ccOUTTNSTTNOUO ROVUOTRQ]ZVXSWOUOd OUUOVQZTNO] O OQUWQZSPU]\S[OQ\TNOPQRSTORQVYbeOWZTO`OTTNOUOPWZOSTWQZUTQNSfO\Q_OVRYWZaPPQ\PSTOSPPYUNW\TWZcgOPQZcSTOVWUTWR]TSY[NSZZOPUTNST[QSPOU[OVTQ\Q_ TNOPQRSTO TNSTRQVYbMNOQRUOfSTWQZ TNOPWZOSTWQZUS OS TQSVWSTO\Q_ TNO \Q_TNO [NSZZOP TNOPQROTSZUWTWQZ WRRQZ TQ hiWcbL[jU]ccOUTUTNST [NSZZOPUTNWUSOd\Q_US[NSZZOP\][STWQZZQVOkO_OcWZc SOd\Q_ TNWU Sf]PUOVSQ]ZV TNOTNWUZQVOR]WPVWZcPQROUNSOV\OST]Obl-A-m3n49541=:/3346o9/3=:4@pdTOZVWZc\Q_ TNOqYSZWUrSPPOUOZTY QWZThiWcbsRjSZVTNO TNOOSUTOZ_ScWZQ\ `QdW_SP Q\\SZgSOSUOWOU RSZ[NWZctuv_wWVOxSTXTQ OVgWRRQZX\Q_UOVW_OZTRQVWOUhRSZ[NOUySZVzjbMNOUONSfOSUW_WPSTNO_SPWZOTWShPQwQZTNOU[SPOQ\ `QdW_SPu{{|U TNO_jTQ \SZ_STOWSPhiWcbJRjb SZV}M~ qW���pVSTSUNQwTNSTQ]T[QUQ\TNOUO WVcOUOdTOZVVWU[QZTWZ]Q]UPY]TQu�{v_ rSPPOUQ]TPOTbMNOZQTNOSUT\Q_TNOqYSZWU PQZcOUT[QZTWZ]Q]UWVcOUO[TWQZU TwQ[POS[Q_`WUO RSZ[NOUg SZVy zhiWcbujbMNOUO rSPPOUQ]TPOTS OS TQ TQRO[QZZO[TOV TNOqYSZWUfWSSZOSUTXwOUTQWOZTOVgOPQZcSTOUOVW_OZT TNSTVOQUWT PWOUSTTNO TNO TNOUQ]TNXOSUTOZ Q\RQ]ZVSY `QdW_SP\SZSZV UQ]TNOZNWcNPSZVUTO SWZhiWcUbu KgSgsSjb zSZ[N�MNWU��Q]TNOZ [POSPY[QZZO[TUwWTN OSUTTNOZQTNOSUT yTOZVWZczSZ[N SZV TOZVWZczSZ[N jgzhiWcbu SPTNQ]cNTNOVOTSWPOV OPSTWQZUNWUSOQRU[]OVRYSZW_ S[T[STOb}Q__OZ[WZc\Q_TNOOVcOQ\TNO_SWZ\SZhSZVTNOOZVQ\TNO�Q]TNOZzSZ[NjRQTNRSZ[NOUy zSZV OdTOZVgVWU[QZTWZ]Q]UPYgST SZV ZQTPOSUT TNOts{v_TQwSVU OSUT ZQTNOSUTbMNOYVQ QfOXPWOQPVO\SZRQVWOUR]TQ[[]Y Q\SZ STSOS TNOOSUTOZ_ScWZTNO TNO`QdW_SP VOQUWT\SZ SZVQfOPWO �]b [Q_`WUOUzSZ[NyTwQ UWZ]Q]UUPWcNTPY U]RXRSZ[NOUTNST\Q_SVWU[QZTWZ]Q]UgQ[X[SUWQZSPPY[QZZO[TOVg[]fWPWZOS STNhiWcbsRjbMS[OVZQTNwSVUgUOc_OZTUQ\ WVcO[QTNOVWU[QZTWZ]Q]U Q]TROTwOOZS[P]UTOQ\ WZTQQ]ZVOVR]TTOURO\QOSUUWZc �QRO VOU[WROV� khiWcbJWZTNOZOdTUO[TWQZjbzSZ[N uLz SWZWTWSTOUSU t v_ xSTXwWVOgTQ OVg_OUSX\Q_WZcUOVW_OZTRQVYhiWcbsRjbMS[OVOSUTwSVUgzSZ[Nz S uZS QwUg\Q_WZc UW_ POgxSTXTQ OVg� v_wWVOWVcOTNSTWUUPWcNTPYUWZ]Q]Uh�ubu�jgTNSTNSUSZS`QdW_STOPY�pX�eXQWOZTSTWQZwWTNbMNOVWUTWR]TWQZSZVUNSOQ\WVcO[Q_ QZOZTUhiWcbsSjWZRQTNRSZ[NOU TNSTUTQZcPYU]ccOUTU TNOY O OUOZTTNOOQVOV Q\O_ZSZTU \Q_OPY_QOOdTOZUWfOUOVW_OZTSYVOQUWTUbMNO] OU]\S[OUQ\RQTNRSZ[NOUgSPTNQ]cNPQ[SPPY[QfOOVWZMy�UgUNQw VWU[QZTWZ]Q]U PWZOSTWQZUUW_WXUTSWcNTTQ[]fWZcPS TQTNQUOQRUOfOVQZTNO] O U]\S[OQ\TNO`QdW_SP\SZhiWcbs[gVjbMNOUOPWZOSTWQZU OPQZXSOQWOZTOVU]RSSPPOPTQTNOcSTWQZVWO[TWQZQ\TNORSZ[NOUb�OTUQ cQ]WZcUQ\TNOUOPWZXOSTWQZUS OS TQ[QUUX[]TOS[NQTNOgSZVPQ[SPPYVOaZOOPQZcSTOWVcOUbMNOUOU]\S[O UTSTWcSNW[TOdT]OUQ[[] VW\\OOZTWZ PSYXOUhu�L_ TNW[vjTNSTNSfO[QZUWUTOZTOPOfSTWQZUgR]T[QUUX[]TQZOSZQTNO MNOUOPWZOSWZ PS[OUb \OST]OUSO SUWZTO`OTOVROVUOTRQ]ZVSWOUOd OUUOVWZPSZfWOw UW_WPSTQQZTNO QdXW_SP\SZRQVYSZVWZ�QRO~hiWcbs[jbMNOxSZvUQ\RQTNWVcOU[QZTSWZ_OTOXU[SPOgU]RXNQW�QZTSPPSYOWZcTNSTWUTS[OSRPOQfOTOZUQ\v_ hiWcb WZTO`OTsVjbeO TNO WRRQZXPWvO\Q_UTQROSPSOQXx]fWSP[NSZZOPROPTUTNSTSccSVOV SPP]fWSPWZSZ UOTTWZcSZVTNSTSOZQw Od OUUOVWZWZfOTOV WZfOTOVOPWO\bMNOOPQZcSTOWVcOUSO SU[QZUWUTOZTwWTNVOQUWTWQZ WRRQZX\Q_ x]fWSP[NSZXZOPROPTUTOZUQ\vWPQ_OTOUWZOdTOZTWZSZSZ[WOZTSPP]fWSP�VOPTSW[PSWZwNW[NU]RUO�]OZTPYRO[S_OTQQcSNW[SPPYWZfOTOVhObcbg}SVOZSUOTSPbg kJ{u�}]OfSU� S T�ZO� OTSPbgJ{u{ MNOjb `OUOZ[OQ\UTSTWcSNW[PSYOWZc WVcOUgwWTNWZTNOUO SZVTNOQ[[] OZ[OQ\

VWfOcWZcUOTUQ\PWZOSTWQZUSSPPOPTQTNOOPQZcSTWQZVWO[TWQZQ\TNO WVcOU `OUOZ[OWU[QZUWUTOZTwWTNSUOVW_OZTSYQWcWZbMNO Q\TwQVWUTWZ[TWVcOUYUTO_U SZVhzSZ[NOUy zjU]ccOUTUSVWUTWR]XTSYUYUTO_wWTN\][STWQZQ\TNOUOUYUTO_UQ[[] WZcVQwZUTOS_Q\ Q\TNO�Q]TNOZzSZ[N jbhiWcbu MNO wWVTN`OUOfOV TNO WVcOUSZVWZTOZSPUT][T]OWUU]ccOUTWfOTNSTTNO WVcOUSOZQT\Q_O[NSZZOPUR]T [NSZZOPSTNO ROPTUbl-�- ��>@5/6?2o4 /31/11>5>23/614�2@>5@525:43295:yTTNOZQTNOZTO_WZSTWQZQ\zSZ[NygPQ[STOV v_tu{{ZQTNOSUT qYSZWUQ\TNO rSPPOUQ]TPOThiWcbujg zSZ[NTNO [QUUOUWUQfOPSWZRYS ScQ] Q\R]TTOUSTTNOOVcOQ\ PQ[SPTQQcSNW[PQwbqOOTNOtuv_wWVO WVcOOdSZVUTQ\Q_SPQRSTO\OSXT]OTNSTWUtu{v_wWVOSZVtuL�J{v_PQZc_QUTPY_SZTPOVRYW_ S[TO�O[TShiWcb�SjbMNWUPQRSTORQVYgwNWPUTPScOPY_SZXTPOVRYW_ S[TO�O[TSWU[Q_`WUOVQ\PWcNTXTQZOV_STOWSPwWTNUTSTWa[STWQZROWZcQRUOfOVwWTNWZWTUOSUTOZU[S`hiWcb�RjbeOWZTO`OTTNWURQVY RQVYbTQROSUOVW_OZTSY Q[v eNWPUTWTWU_SZTPOVSZV STWSPPYQRU[]OVRYS OPSTWfOPY\OUNW_ S[T[STOgTNO \Q_ TNOTSZUWTWQZ S WRRQZ\Q_ WVcOWZTQ PQRSTORQVYWUwOPP`OUOfOVbyvOY\OST]OQ\ VOQUWTTNWU WU WTWUTNST PQ[STOVwWTNWZTNO O_ZSZTQ\S�{Xv_XVWS_OTO cNQUT[STOgTNO W_ Q\wNW[NWUVO_S[STOVRYS WZcQ\_OUSUhiWcb�SjbzSZ[NyWZfOTOV[NSZXZOP[QUUOUTNO W_ Q\TNOcNQUT[STO RO\QOUNQwWZcOdSZUWQZTQ\Q_TNOPQROVOQUWTgwNW[NWUUOTwWTNWZ TQQcSNW[S VOX`OUUWQZVOaZOVRYTNO[STO hiWcb�SjbMNWUU]ccOUTUTNSTTNOPQROWUS\SZVOQUWTPQ[STOVSTTNOOZVQ\TNOUOVW_OZT STNwSYZQwO OUOZTOVRYTNO [NSZZOPWZfOTOV \Q_gSZVWTUVOQUWTWQZNOO_SYROSUUQ[WSTOV TNOwWTN SPSOQTQQcSNYQ\TNO�{Xv_XwWVOW_ S[TUT][T]OhiWcb�SjbiQTYvWPQ_OTOUTQTNOZQTNQ\�QRO�gSVWU[QZTWZ]Q]USZVVOcSVOV QUUWRPOUOWOUQ\ O OUOZTWZcQ]T[QU O_ZSZTUQ\WRRQZX\Q_ UOc_OZTUQ\WZfOTOV[NSZZOPU VWUXSO STQRUOfOVg STSZ[Otu�{v_ \Q_ TNO_SWZqYSZWUQ]TPOThiWcbujb�]\S[OTOdT]OUQZTNOUOQ]T[QU QRUOfOVSOUW_WPSTQTNQUO QZTNOWRRQZX\Q_ UOVW_OZTRQVWOUTQTNOUQ]TNg TNOYU]ccOUTWZc PWvOPYO OUOZTTNO_QUT _QUTZQTNOPYSZV RSUWZwSV O_ZSZTUQ\TNOqYSZWUVOQUWTWQZSPUYUTO_ MNOUOhiWcb�[jb UT][T]OUQ[[] STSZOPOfSTWQZQ\t�K{JL_ R]TSOZQT[QZaZOVWZSZQTNwSVUVWO[TWQZ Q\RYSZY_STOWSP TNOUS_OScOQQPVObMNWUW_ PWOUTNSTTNO TNORSUWZWZaPPOVUO[TWQZQ\ RYTNOUOUOVW_OZTSYVOQUWTUWUgSZV STSP_QUT[OTSWZPYwSU TW_OQ\VOQUWTWQZgTQQcSNW[SPPYQOZTQTNOZQTNOZ PSWZUQ\ hiWcUb�SU J�gjb�QOQfOgTNWUWZXVW[STOUTNSTVOQUWTUQ\TNOqYSZWUUOVW_OZTQ]TWZcUYUTO_Q[[]_SZYTOZUQ\vWPQ_OTOURSUWZwSVUQ\ U]ccOUTXTNOqYSZWUQ]TPOTWZcOdTOZUWfO`QcSVSTWQZQ\TNOUYUTO_bl-�- 2�?/54�@5/�4492@>23 5:4@41>�435�/3MNO `OUOfSTWQZ Q\ `QdW_SPTNO \SZgSZV TNO SUUQ[WSTOVRSZ[NWZc WRRQZXPWvO WVcOSZV VWUTSPPQROUWZWZfOTOV OPWO\WZVW[STOU U][[OUUWQZTNSTTNOUOVW_OZTSY NSUOdOWOZ[OV QUTXVOQUWTWQZSPSZV QUTXPWTNWa[STWQZOQUWQZh�WzWSUOOTSPbgJ{uKkeWPPWS_U �  ¡OTSPbg jbMNOWZfOUWQZQ\ OPWO\`OUOfSTWQZUTYPOh�SWZOTSPbg kJ{{��SWZSZV ¢ WPWO^g u��LjQ[[]UwNOO_QOUWUTSZT_STOWSPUS_Q]TNOU]\S[OScSWZUT wNWPOOQUWQZg SVX�S[OZTPOUUXOUWUTSZT_STOWSPUSOVOZ]VOVhz]^OTSPbgJ{{�k�SWZ �  £¤OTSPbg �SWZSZV ¢ WPWO^g ku��L eWPPWS_UOTSPbgJ�SfWU � ¥¦OTSPbg jb§WfOZTNO UOTTWZcTNO[NSZZOPcOQPQcW[SP VOXQUWTUSO`QRSRPY`OVQ_WZSZTPY[O_OZTOVUSZVUTQZOUSUWZX\O OV\Q_ TNOPSYOWZcgSPROVQgTNO_SP wWTNWZOTWSgSUUQ[WSTWQZMy�UgSZVRYSZSPQcYwWTN hz]^UW_WPS PSZV\Q_UQZpSTN OTSPbg kJ{{�}]OfSU� S^T�ZO� OT SPbg J{u{k OTeWPPWS_U SSvW � ¥©OTSPbg jbMN]Ug_STOWSPUVOQUWTOVWZTNOPScO [NSZZOPU

Page 13: Open Research Online › 56400 › 1 › The Hypanis Valles delta_ The last... · Open Research Online The Open University’s repository of research publications and other research

��������� ���� ���������������������������������������������

��� ����������������� ���������!�"#$�!%&"�%'$!�("(#)!$�$(�'!'�%�")%*'("%))$#+�*�+�!&#(����$("�)")%*���&&*%(#()����'*)��#(�%(%*+ ����'

,-. /012345678290:;2<8=264/926782<>?@A76@7B7887<CDEEFGEHIJGGDKGLH

MNOPQPRSTUVWVXUWYXVZSZ[UW\]Y \_Y XYaZYbVc WdY eU[[Y WdYf\WX\gZW\hbT[hWi\WdjWWYfShfY[UkY hXlUm ZbbUSYfVXUWYX Ubfln\ko,gm lgmpcTUb\ Z\bk gZ YXYfVXUWYXVhZbW\bkSYWdhfhnU YWWUbfpYUfl,qqrmosdYfUWUUXYVhb\WYbWi\WdhgYX]Yf ZTYXTh\W\hbXY[UW\hbd\T WdUWZkkYWpcTUb\eU[[Y \h[fYXWdUbWdYZbbUSYfVXUWYXosdY \bf\VUWY \bf\VUWYtlum]U[ZY hXghWd UbYUX[c UkYopYTYX\Ub hXSUW\hb tlqovm]U[ZY U pYTYX\Ub pYTYX\Ub[UWY XYWYbW\hbUkY hXWdYZbbUSYfVXUWYXUbfUbYUX[c UkYhX hXpcTUb\owhhWx,g\bbYf\bVXYSYbWU[ l,qqvm\_YxXYaZYbVcT[hW lVmWdY lfm eU[[YZbbUSYfVXUWYXUbf pcTUb\ gZ YXYfVhZbWosdYtlumUbftlqovm]U[ZYZkkYWUb VXUWYXUkY VXUWYXo Ubh[fYXUkY thUVd\UbUbfYUX[cpYTYX\Ub hXWdYZbbUSYf tlumUbftlqovm]U[ZY hXpcTUb\eU[[Y ZkkYW h [UWY YUX[cpYTYX\UbyXYTYVW\]Y[coTXhgUg[cTXhWYVWYffYTh\WgYbYUWdWdYSyid\[YjbYXxkXU\bYfU[x[Z]\U[SUWYX\U[ ZVdU SZffczhhfT[U\bfYTh\WiYXYXYSh]YfosdYYXh\hbTXhVY^WdUWT\V{YfxhZWWdYY YUWZXY\b\b]YXWYfXY[\Y iU TXYZSUg[ci\bfxUVW\hbyUVW\]Yh]YX Y]YXU[g\[[\hbcYUXh d\WhXcoSUXW\Ub phiY]YXy ghfcWdYSU\b Ub U[h dhi^Y]\fYbVY hX[UWYxWUkYzZ]\U[YXh\hb|U u} {S i\fYVdUbbY[\bxV\Y WdYZTTYXZXUVYln\ko-Umosd\ ZkkYW[UWYXzZ]\U[zhiWhU l[hiYXgUY[Y]Y[~�,�vqmWdUbiU TXYYbWfZX\bkWdY hXSUxW\hbhWdYSU\b Ubghfcl}�,�vqWh}�,.vqmid\Vd\WVZWWdhZkdo�0I0 5� 5��A�A6� C74A�76828A56 8=7�>�26ACC74A�768�26sdY eU[[YiYWYXbUbf hZWdYXb pcTUb\gXUbVdY h hX\k\xbUWYi\Wd\bWdYVhbW\bZhZ Y�YVWUg[Ub{YWhU}�q{S f\USYWYXZbbUSYfVXUWYX\bWdYpcTUb\ hZWdYXbVUWVdSYbW sdYln\ko,mogXUbVd UbfdUTUXU[[Y[ eU[[YWdYf\WU[XYUVdh tUbYf\ UXY[UxW\]Y[c[hii\fWdh }-qqSosdYiYWYXbgXUbVdYSYXkY i\WdUi\fWdh }uo,{So�hWdVdUbbY[ dhi V[YUXWXZVWZXY UbfWhxThkXUTd\VY�TXY \hbY�VYTWidYXYWdYcUXY ZTYXThYfgcWdYY�YVWUhWdYZbbUSYfVXUWYXyid\VdSZWYWdY WXZVWZXYUbfWhxThkXUTdchWdYVdUbbY[osdYYhgYX]UW\hbyVhZT[Yfi\WdWdYZTYXTh\W\hbh YVhbfUXcVXUWYXVdU\b XhS WdY USYZbbUSYfVXUWYXy\bf\VUWYWdUWpcTUb\ TXYxfUWY Wd\eU[[Y WdY hXSUW\hbhVXUWYXo�s�xfYX\]Yf\STUVWVXUWYXWUW\W\VWU{Yb XhS WdYVXUWYX�VhbW\bZhZ Y�YVWU hg[Ub{YW\bf\VUWYUtlum]U[ZY �.-qVXUWYXTYXuq.{S,osd\YaZUWYWhUbYUX[cpYTYX\UbUkYZ\bkghWdpUXWSUbbl m,qqvUbfR]Ubh]YWU[ol m,qquTXhfZVW\hb ZbVW\hb UbfWdY VdXhbh[x�\VdUY[l m m,qu- UbfpUXWSUbbUbftYZ{ZS l,qquhkc ZbVW\hb ln\kormo�Z YXYfVXUWYXVhZbW hbpcTUb\ eU[[YyZ\bk \S\[UXghWdWdYu - UXUf\\Ubf XUf\\SYWdhfy\bf\VUWY YUX[cpYTYX\UbUkYgUYfhbWdYtlum]U[ZYZ\bkWdYR]Ubh]YWU[ol m,qquUbf ������� �pUXWSUbbUbf ����TXhfZVW\hbUbfVdXhbh[xhkc ZbVW\hbo�\bkWdYpUXWSUbbl m,qqvyUbf�\VdUY[l m,qu-ZbVW\hbyWdYtlum]U[ZY ZkkYWU[UWYthUVd\UbUkYo�hWdWdYZTYXTh\W\hb gYWiYYbXY[UW\hbd\T WdYZbbUSYfVXUWYXUbfpcxTUb\eU[[Y UbfWdYVdXhbh[hkcfUWUUXYkYbYXU[[cVhb\WYbWi\WdTXY]\hZ UkY mWdUW pcxVhbWXU\bWlnU YWWUbfpYUfy,qqr T[UVYf

Page 14: Open Research Online › 56400 › 1 › The Hypanis Valles delta_ The last... · Open Research Online The Open University’s repository of research publications and other research

��������� ���� ���������������������������������������������

��� ����������������� ���������!�"#$�!%&"�%'$!�("(#)!$�$(�'!'�%�")%*'("%))$#+�*�+�!&#(����$("�)")%*���&&*%(#()����'*)��#(�%(%*+ ����'

,-./012345/6-78/95:/31,6/345/9;<=>43=4?45549@ABBCDBEFGDDAHDIE JKLMNOPQ RS RSTPUVPOUVWXNUWQUQUNYW UVW ZXP[NUWWN\X] RMUP[ [ _NXXW]OWUTR\ KabSR\[NUPROcNUd eNc fWQMW\PNOPOUVWWN\X] gh\TPO NXacWUJiijkalmnopqrsqstuvqwxwyvtrzrtvqvwoy{orv|t}~zqyw�{qy�~�vt�hU\W[NPOQ�P�ZXUUR�PQUPOYPQV�_PNXSNO�WMRQPUQRO�N\QS\R[ S\R[�WXUNPZ�R�PWQ R\�PUNX[R\MVRXRYPZNXNONX]QWQNXROWa�\W�QW\_W�SNO\W[ONOUQ �WXUNRO RS�N\QN\WORUW�NZU[P[PZQ YW�R[R\MVRXRY]NQUVWQU\NUPY\NMV]\WM\WQWOUQUVWUP[WPOUWY\NUW�W_RXUPRORS RS�WXUNPZM\RZWQQWQa�VWN�QWOZW TWXXW�MRQW�W��V[W�MXNOSR\[QRSNOZPWOU�_PNX�WXUNQRO�N\UVXP[PUQZR[�MN\PQROUR[N\UPNOW�N[MXWQcOXPWTPUV�_PNXQ]QUW[QafW\WcTWMRQPU MNXNWRYWR[R\MVPZRO RSUVW�NQPQ R�QW\_NUPROQUVNUUVWf]�MNOPQQW�P[WOUSNO\WM\WQWOUQNONOZPWOU[N\UPNO�WXUN�WMRQPUW�NUUVW QUNO�POY UVW hO[N\YPORSN TNUW\�R�]PO �V\]QW�NQPOaPUQM\R�P[NX\WYPROc Q][[WU\PZUVWf]MNOPQSNOSR\[QN\N�PNXX]MNXNWRYWR[R\MVPZSWNU\WPOMXNOSR\[UVNU�W_WXRMW�P[[W�PNUWX]�RTOQU\WN[RSUVWf]MNOPQ�NXXWQ�W�\RZ ZVNOOWXRUXWUa�WMR�QPUPRORSUVWSNONUUVPQXRZNUPROPQXPWX]UVWZROQW�WOZWRSUVWU\NOQPUPROS\R[ UVWZRO�OW[WOURS�RTPO MXNO��W�\RZ ZVNO�OWXURN�NQPOTVW\W�RTPQ OZRO�OW�gWaYac�XNP\NO��Z�VW\QROc������PUUROPWUNXacJi��kafW\Wc\W�ZUPROPOZVNOOWX�W�NO�TN�UW\Q\SNZWQXRMWQ\W�ZW�UVWQW�P[WOUU\NOQMR\UZNMNZPU]XWN�POYUR URWOVNOZW��WMRQPUPROM\R�P[NX UVW_NXXW]RUXWUahO UVW�WUNPXc\N�PNXX]Q][[WU\PZ �WMRQPURS M\R�P[NXMXNOSR\[ UVW f]MNOPQSNONMMWN\QURZR[M\PQWNON[NXYN[NUPRORSQW_W\NXXR�W�XPW\W[�ONOUQRSSR\[W\X][R\WW�UWOQP_W�WMRQPUQa�OWPOUW\M\WUNUPRORSUVWM\R�P[NX RSSNOPQ PUUVNU TNQ N_XQPROSR\[W��] \P_W\ZVNO�OWXQN\RO�UVWURMRY\NMVPZNXX]MPOOW�OR�WRSUVWf]MNOPQRU�XWUcTVPZVZ\WNUW�[ XUPMXWcXNUW\NXX] �WMRQPUQaQUNZW� hOUVPQZNQWcUVWRUXWU �W�QXRMW�[W�PNUW�SR\[QN N_XQPROOR�WgeNOUP NXacWUJi��ka�R\UVWM\R�P[NXSNOcPUPQ OZXWN\TVWUVW\PU\WM\WQWOUQNM\WX]�_PNXSNOR\N�WXUNPZ�R�]a ORUWVRTW_W\�W UVNUUVWQU\NUPY\NMV]M\WQW\_W�RO M\R�P[NXUVW SNOW�V[W�Q\SNZWZR[�M\PQWQ\WXNUP_WX]QU\NPYVUURQXPYVUX]Z\_W�XPOWNUPROQUVNU\N�PNUWRUTN\� RUXWUaS\R[UVWf]MNOPQ �WPOUW\M\WUUVWXPOWNUPROQNQM\WQW\_W��W�QWU�RO�N\PWQNO��R\ZVNOOWX[N\YPOQW�MRQW�ROUVWMXNOSR\[ Q\SNZWa�RW_P�WOZWSR\QPO RQZVNOOWXQZVN\NZ�UW\PQW��]XNUW\NXNZZ\WUPRO�W��POYcNQ\WZR\�W�PO�RUVUVW�W�W\RNO���W\QTNX�WQ]QUW[QcPQR�QW\_W�g�VNUUNZVN\]N �WUNXacJiijeR�YW ��� WUNXac ka�VWM\WQWOZWRSXPOWNUPROQQVRTPOYNXN\YWQM\WN� S\R[UVWPON�P[ UVW[NONUPOY �W�\RZ RUXWUPQQYYWQ�UP_WRS�WMRQPUPRO�][ XUPMXWZVNOOWX�R�PWQUVNUVN_W�WZR[WXNUW\NXX]QUNZW�NO�S\UVW\QYYWQUQS\W�WOUN_XQP_WQVPSUPOYRSZVNOOWXQ�RTOQU\WN[RSUVWRUXWUa�PQZ\WUW\P��ROZVNOOWXQN\WORUR�QW\_W�a�VPQPQQP[PXN\URZVNOOWX��XX�WMRQPUQ�WQZ\P�W��]eR�YWWUNXag kJi�LS\R[ UVW UVWMMW\[RQUM\WQW\_W�Q\SNZWRS�W�W\R N�WXUNcTVPZVUVW]POUW\M\WUNQ�WMRQPUPROS\R[ VPYVX]N_X�QP_W�_PNXQ]QUW[ OWN\ UVWR\TPUVPO �NZTNUW\�ROWRSN�WXUNa�ZVN[R�WX[N]NXQRNMMX]URUVWM\R�P[NXf]MNOPQ�WMRQPUQa�R\WR_W\cTWORUWW_P�WOZWPOUVWM\R�P[NX RSSNOSR\�P_W\YWOZWXPOWNUPROQc VWOZWNO� ZVNOOWXR\PWOUNUPROc UVWTPUVPO SNO�R�]PU�QWXSTVPZVTWPOUW\M\WUUR\WM\WQWOUZVNOOWX�PS\ZNUPROQPO�RTO�QU\WN[XRZNUPROQROUVWSNONO�ORU¡QUNUUVWRUXWUZR[MN\N�XWUR�PQU\P�UN\]SWNU\WQR�QW\_W�POUW\\WQU\PNX�WXUNQg�VN[�W\XNPOWUNXacJi�¢ SNO�URMS\ZNUPROQka�ZV N\W �PQU\P�UN\]U]MPZNXRSZVNOOWXQPO�WXUNURMWO_P\RO[WOUQahOUVPQZNQWc OR�WQN_XQPRORZZ\POUVW�NZTNUW\�ROWcN\WYPROZVN\NZUW\PQW��]VPYVTNUW\Q\SNZW _N\PN�PXPU]QXRMW NO�TVPZV QMNUPNXQVRTQ �RT�WZWXW\NUPRONO� NU�WMRQPUPRO XRT �RTQUW\[W�£�NZTNUW\�[W�PNUW�¤N_X�QPROQg�VNUNONOUN_WU Ji�J�WUNXac �VNUNONOUN_WUNO�¥N[�cJi���eNOUP ���¦WUNXac ka�VWM\R�P[NXf]MNOPQSNO�WMRQPUQQVRT�PS\�ZNUPRORSZVNOOWXQ�RTOQU\WN[ RSUVWRUXWUcVRTW_W\UVWM\WQW\�_NUPRORS�PQUPOZUMNUUW\OQTPUVVPYV�PS\ZNUPRONOYXWQPQXP[PUW�a

�VW[RQU�ZXWN\W_P�WOZWSR\N�WXUNPZR\PYPOSR\UVWf]MNOPQQ]QUW[ Q]QUW[ZR[WQ [R\MVRXRY]RSS\R[ UVW �VNOOWX�¥R�W §g�PYajkafW\WcSR\[NUPRORS �WMRQPURZ�NON\ZNUWXR�W�QVNMW�Z\Qdji [ �RTOQU\WN[ RSUVWf]MNOPQRUXWUcR_W\QUWMMPOY�W�]RO�UVW�WMRQPUPRONXW�YWRSUVWM\R�P[NXSNOa�WM\RMRQWUVNUUVW UVW UVWZVNOOWXXR�W�QVNMW��WMRQPUSR\[W�NU [RUVRS �WURMRX]S\ZNUPRORS�PQU\P�UN\PWQS\R[ UVW[NPOZVNOOWXa�PUVPOUVWXR�WPO�P_P�NXZVNOOWXQZNOORU�WR�QW\_W�UVRYVXPOWNUPROQN\WR�QW\_W��P_W\YPOYS\R[ UVWZVNOOWXROUVW MMW\Q\SNZWRSUVWXR�Wa UVWZVNOOWX�XR�W�WMRQPUUVNU U\NOQPUPRO\WM\WQWOUQN MRPOUS\ZNUPRO RSUVW�WXUN�PQU\P�UN\]OWUTR\ NO�\WZR\�QNMNXNWRQVR\WXPOWMRQPUPROg�VN[�W\XNPOWUNXacJi�¢ka [MXPU�WQU\NUNXQXPZWQUV\RYV QWPQ[PZK� �NUNNZ\RQQ�WXUNPZQZZWQQPROQQVRTQP[PXN\�W_WXRM[WOU XR�WQRS�WXUNPZ �W_WXRMW�NUUVWWO�QRS M\RY\N�W��PQU\P�UN\PWQNQ Q]QUW[Q�WXUNPZ �NQPOTN\�Qg©WOYWUNXac c �VWJi�KJi�Jka XRZNUPRORSUVWZVNOOWX�XR�WU\NOQPUPROPOQ]Q�UW[§OR\UVRSUVWM\R�P[NXSNOPO�PZNUWQN[N¡R\�NQPOTN\�¡[MPOUVW UVWXRZNUPRORS MNXNWRQVR\WXPOWa�VPXQUQZVNM\RZWQQRS�RTOQU\WN[[PY\NUPROPOXRZQRS�W�MRQPUPROPQMRQQP�XWPO�_PNXSNOQTVW\WSWW�W\ZVNOOWXQPOZPQWUV\RYVM\R�P[NX �WMRQPUPROSNO�WMRQPUQcNO�OWT XR�W RZZ\Q�RTOQU\WN[ ZVNOOWXcRSUVWPOZPQW� NU ORUf]MNOPQTW�R R��QW\_WW_P�WOZWUVNUUVWSWW�W\ZVNOOWXUR¥R�W§PQPOZPQW�POURM\R�P[NX \XPOY�WMRQPUQUVQ RUUVWN�R_WV]MRUVWQPQahOQUWN�cTWQYYWQUUVNUUVW�NQPOTN\��QUWM ZROQW�WOZWRS¥R�W§PQUVWRS [PY\NUPRORS�RTOQU\WN[ N�NZTNUW\�[W�PNUW�N_XQPROQPUWahOUVW UVWZNQWRS�VNOOWX�XR�WQ]QUW[ §c N_XQPROOR�WVNQ[P�Y\NUW��NQPOTN\�QPYOP�ZNOUX]ZR[MN\W� M\R�P[NXURUVW SNO\N�PQ\WQXUPOYPONVPYVX]WXROYNUW�MXNOSR\[ YWR[WU\]gWaYac�PYa�POeNOUPWUNXacJi��ka�WQYYWQUUVNU�NQPOTN\�[PY\NUPRORSUVW�ROW U\NOQPUPRO PO�PZNUPOYRSZVNOOWX�XR�W PQUVWZ\ZPNXW_P�WOZWUVNU QW�P[WOUUVWf]MNOPQ SNO\WM\WQWOUN�WXUNUVNUM\RY\N�W�POUR RS ZR[MXW� RSNQUNO�POY�R�] TNUW\a�VWSNO TNQZR[MRQW�[ XUPMXWZVNOOWXQNO�XR�WQg�NO�P¡WUNXacJi�JcJii�kcTVPZVSR\[W�NU �R�]UVW QUNO�POY[N\YPORSNXN\YWc RS RSTNUW\a�NO]UVWQWZVNOOWXQNO� VN_W NO�N\WORTXR�WQ QPOZW�WWOW�V[W�M\WQW\_W�POPO_W\UW�\WXPWSa�VWQW�P[WOUN\]MNXNWRYWR[R\MVRXRY]NUf]MNOPQPO�PZNUWQS\UVW\QPYOP�ZNOU�NQPOTN\� QW�P[WOUM\RY\N�NUPRORSUVW SNOQ]Q�UW[a�VWPO_W\UW�ZVNOOWX�\NOZVWQM\WQW\_W�NUUVWWNQUW\O[N\�YPORSUVWM\R�P[NXSNOg�PYabkc�W[ROQU\NUWUVNU�_PNXQW�P[WOU\RUPOYQ]QUW[QU\NOQMR\UW�QW�P[WOU MURNUXWNQU�ii [ OR\UV�WNQURSUVWf]MNOPQRUXWUPO�PZNUPOYQPYOP�ZNOUW�MNOQPRORSUVWf]MNOPQQW�P[WOUN\]Q]QUW[ �V\]QWOR\UVRSUVW WQZN\M[WOUNO�UVW§NOUVW URRc RS�W\\N MXNO�QafW\W TWR�QW\_WNOW�N[MXW N[N¡R\�NQPOTN\�¡[MPOUVW UVWZVNOOWX�XR�WU\NO�MRQPUPRORSQPUPROcNQW�W[MXP�W��]¥R�Wªg�PYaLkahU\W[NPOQ�P�ZXUURW�MXNPOUVPQZVNOOWX�XR�WU\NOQPUPROPONM\WX]�_PNXSNOQWUUPOYaOP[MR\UNOUR�QW\_NUPROPQUVNUUVWWXW_NUPRORS�WMRQPUPRORS RS RZZ\ZVNOOWX�XR�WQW�P[WOUQ UVWf]MNOPQQ]QUW[ NUM\R�Y\WQQP_WX]XRTW\WXW_NUPROQTVWOU\NZW��NQPOTN\�URUVWOR\UVa�WMRQPUQRS M\R�P[NX RZZ\ RSUVW SNO NUNOWXW_NUPRO d«Jjii[cTVW\WNQ�WMRQPUQRS RZZ\¥R�Wª NUd«JLii[cNO��WMRQPUQS\�UVW\�NQPOTN\�N\WM\WQWOUNUNOWXW_NUPRORSd«Kiii[a�VW[RQU �RUV �NQPOTN\�MN\QP[ROPRQW�MXNONUPROSR\ UVW [PY\NUPRORSUVW ZVNOOWX�XR�WN_XQPROOR�WgUVW U\NOQPUPROkNO�PUQ�RTO�QUWMMPOYPOWXW_NUPROPQUVNUUVW �_PR��WXUNPZf]MNOPQ Q]QUW[\WZR\�Q UVWM\RY\N�NUPRORS QW�P[WOUN\]Q]QUW[ �\POYM\RY\WQ�QP_WSNXXPO�NQWXW_WXUV\RYVNdjii[WXW_NUPROZVNOYWcTPUVUVW�NQWXW_WX\WM\WQWOUPOYUVWWXW_NUPRORSNQUNO�POY�R�]RSTNUW\a�VPQNQQ[WQUVNUUVW�NQPO�RR\NO� N\WMQU\WN[\WYPRO UWZURO�PZNXX]QUN�XWcTVPZVPQXPWX]_NXP�SR\�N\Q MURUVWYXR�NXQZNXWgWaYa¬O�W\QROWUNXac �Jii��PU\ROWUNXacJi�¢ �VWka QZNXWRSUVWf]MNOPQ OWN\�]�WXUNZROU\NQUQTPUVUVW �N�\PON�NXXWQSNOQ]QUW[cTVPZV �NQPOTN\��QUWMMPOYPQQ[NXXW\NO�VNQORR�_PRQ SNO\W[�ONOUQgfN�W\ Jii�WUNXac ka

Page 15: Open Research Online › 56400 › 1 › The Hypanis Valles delta_ The last... · Open Research Online The Open University’s repository of research publications and other research

��������� ���� ���������������������������������������������

��� ����������������� ���������!�"#$�!%&"�%'$!�("(#)!$�$(�'!'�%�")%*'("%))$#+�*�+�!&#(����$("�)")%*���&&*%(#()����'*)��#(�%(%*+ �+��'

,-. /012345678290:;2<8=264/926782<>?@A76@7B7887<CDEEFGEHIJGGDKGLH

MNOPQPRSTUVWXY ZT[T\X]UT__VaT b _ST Xc_ST dV\\Tef]Vb TZbUT_ f_TUcV aXbagVhijVYZ b _bUTk VRST\Tc_SXj` b\\l_YV_b[Tmn_XophYX qTh_bX jb_SgYbaS__XTbZbhV_ba VZ_STVh_b[T]YXhT T _STYbaS_SXj hXYYT]XZba _VaTXc Xl_hYX]k]\V [bTjUXY]SX\Xafb_SThX_TU]XYVYf rTb_V_shXVYTYqaYVbTZUV_TYbV\bbZbhV_TZ ZVYiaYTT bZbhV_T\VfTYbapsgf m\bT \T YTb_V_tTYqaYVbTZ VZT]Xb_VYTbZbhV_TZgf\baS_aYTTu_STvl[bV\YTabUTb g\lT\bTVZV__STTZaTXc gXZfXc XcV _VZba jV_TYb bSXj^ g\lTkw\X SXj^VYT VYT_STYXlZTZgl__TsjSbhS YTU V_ VYTabXV\s\XjYTb_VhTX[TYglYZTkxYXU_ST _STVgX[ThX bZTYV_bX sjThX _Ylh_ cX\\Xjba hTqVYbXV V]X bg\T TylThTXcT[T_ b _STZT]Xb_bXV\Sb_XYfXcef]VbdV\\T mxbakzpk{k|T]Xb_bX Xc_STVYhlV_T]YX}bUV\ XccV V_VgVT\T[T\~�,���U VgXl__STgTZYXhiqhXtTZXl_\T_Xcef]VbdV\\TkRSTcV gXZfhXU]YbT VhXU]\T} XcV TUg\VaT \V_qTYV\\fUTYaTZ \XgT VZ cTTZTYhSV T\ jb_S V VYTVXc�z��iU,k,k�YXaYVZV_bX Xc�SV T\q�XgT f_TU �k|lYba_STtY__VaTXc XcZT]Xb_bXgVT\T[T\cV\\s_ST\Xhl Sbc_TZgVbjVYZVZ cVk�XgT� _T]]TZXl_cYXU_ST]YX}bUV\-k�}_T bXXcvl[bV\f_TU` XY_SqVZ XY_STV_qjVYZ V__STTV_TY UVYab Xc ]YX}bUV\_ST l]_X~{��iU gVbjVYZ Xc_STef]VbXl_\T_k�k|T]Xb_bX Xc�XgT�V__ST_TYUbV_bXXc�[TY_TZ�SV T\�YVhSwk�X_blTZ XcVZ[VhT _STZT]Xb_bXV\\Xhl ZlT_XgVT\T[T\cV\\_X~�,���Uk

Page 16: Open Research Online › 56400 › 1 › The Hypanis Valles delta_ The last... · Open Research Online The Open University’s repository of research publications and other research

��������� ���� ���������������������������������������������

��� ����������������� ���������!�"#$�!%&"�%'$!�("(#)!$�$(�'!'�%�")%*'("%))$#+�*�+�!&#(����$("�)")%*���&&*%(#()����'*)��#(�%(%*+ �%��'

,-./012345/6-78/95:/31,6/345/9;<=>43=4?45549@ABBCDBEFGDDAHDIE JKLMNOPQRSTQUVWXYZVQ[ WT[X\TYRT]RTYWXY _RST QPRXY WaWbRT\ VY[[TcWXRXY_[XWRVd_VYTdT\TYRWVRVUVWTdTeTd_fgKhhh\NiNjTYP[VRXYVY[kSVYYTdU[aXYeTQWXYNlTdXVYTQWXY[TbmVRT[RSTdVY[WPQ_VkTncQT_TQTYRXVddaQT\ eXY dTWWbQTWXWRVYR\VRTQXVdW ZSXkSRSTQT\VXYXY PRkQcW _ VQTdXoTdaR UTRSTXWdVRT[ RSTQPY[T[UPRRTW kQTVRXYVY[kQPkXVdda XYeTQRT[kSVYYTdU[XTWpOXWNqirnn VY[WPccdT\TYRVQa\VRTQXVdsNtuvwxyzw{|}w~��w����STcVdVT\ QcSd a VQkSXRTkRPQT _VY[WRQVRXQVcSXk RST�abcVYXW_VYk\cdT]VQTkYWXWRTYRZXRSXYXRXVd[TdRV[TcWXRW_Q\XYVRVYTdTeVRXY _fgJMhh\N�STWaWRT\ RSTYcQ QV[T[UaVRdTVWR�qho\ UVWXYZVQ[W VYXYQTWcYWTR RVUVWTdTeTd_Vdd TdbTeVRXY _fgKhhh\N�SXW QTcQTWTYRW_VddXYUVWTdTeTd \ QTRSVYSVd_ kSVYTVeTQRXkVdoXd\TRQT _ZVRTQbdTeTdkSVYTN�SXWQTdVRXeTXW\ QT RSVY VUWdPRTX\cQRVYR RST TdTeVRXYWUTkVPWT _RSTcWbWXUdTXYmPTYkT_ dUVdWkVdTkQPWRVdmT]PQTn�XRQY sTRVdNpJh��QTcQRRSVRRSTVQTV _RST�acVYXWWT[X\TYR_VY\VaSVeTUTTY[XWcdVkT[ cdVQ [TeTdcbUag�hhh\ RQPT[PTR ZVY[TQVY[RST\TYR _�SVQWXWN�STX[TYRX�kVRXY _[TdRV[TcWXRWSTQTcQeX[TWTeX[TYkT_QVdVQTWRVY[XYU[a_ZVRTQRSVRdXoTdaUTVYRQTRQTVRVRRST RSTWRVQR _ �TWcTQXVYN�\cQRVYRdanRSTUVWXYVRRST [ZYWdcTPRdTR �VddTW_�acVYXW XWcTY R�SQaWT�dVYXbRXVnZSXkSXYRPQY cTYW[ZYWdcT YR RSTYQRSTQYcdVXYWN�STXYRTQcQTRVRXY_ cQ QV[XYRST�acVYXWWT[X\TYR_VYVWV [TdRVWaWRT\ XWRSTQT_QTVdW TeX[TYkT_QRST [T\XWTT]XWRTYkTVY[ _VQTXYVdU[a_ZVRTQZSXkST]RTY[T[VkQWW�SQaWT�dVYXRXVnVY[cRTYRXVddaTeTYVdVQTQbWkVdTZVRTQU[a VY RSVR� kTVY�\XSRSVeT VkQWWT]RTY[T[ RST RSTYQRSTQYcdVXYW _�VQW[PQXYTVQda�TWcTQXVYpOXN�sN�ST\V]X\P\TdTeVRXYpfgJMhh\s_ XYRRSTZVRTQU[aZSXkSRST RST\VXY�acVYXWWT[X\TYR_VY_Q\T[XWWX\XdVQR TdTbeVRXY_RST�VUQXYV�VddTW_VY PRdTRpOXNJsN�RXWVdW eTQaWX\XdVQRRSTTdTeVRXY_\ QcSd XkVd _XY[XkVRQW VcWWXUdTYQRSbTQY kTVYSXSWRVY[nXYkdP[XY pXsRSTcQcWT[ T\ QcSXk�kYbRVkR��VY[�lQVUXVWSQTdXYT�ZSTQTRSTRSTQTRXkVd[XWRQXUPRXY _WPQ_VkT kXQkP\WkQXUTZVRTQ[PQXY TWRX\VRT[RST� VkSXVYXW R RSTYQRSTQYdZdVY[W JMMh KK�hUTRZTTYg \ VY[g \ p�dX__Q[VY[�VQoTQnJhh�sn JMqh\ ��rVY[ VRpXXsRSTT�PXcRTYRXVdWPQ_VkT g �pZXRSVWRVY[VQ[[TeXVRXY_f�Jh\s_jXlkSXddTVY[�aYTop sJh�hkVdkPdVRT[_Q\ RSTTdTeVRXY _MJWT[X\TYR_VYW UWTQeT[Y _RST\VQXYW RSTYQRSTQYdZdVY[WpYRT�RSXWWRP[aXYkdP[T[RST RSWT�acVYXW_VYsN�YdXoT cQTeXPWXYeTWRXVRXYW_cWWXUdTkTVY ZSXkSX[TYRX_aWSQTdXYTW T\ QcSXk V_TVRPQTWVkQWW ZX[TVQTVVR QVYTV _TdTeVRXYWnZTWcTkX�kVddaX[TYRX_aRSTQVYT _TdTeVRXYW RSQPSZSXkSVRVWXYdTdkVRXY RSTdTeTd_RSTZVRTQU[a_TddpgJMhh\ R fgKhhh\s[PQXY mPbVcTQX[ZSTYeXVdcQkTWWTWZTQTWRXddVkRXeTN�SXWcQeX[TWV\XYX\P\ QVYT _TdTeVRXYW ZSXkS kTVYbQTdVRT[WSQTdXYTZXRSXY RSTQ dVY[_Q\WkPd[SVeTT]XWRT[VdY RSTSXSdVY[bdZdVY[[XkSR\aN�_kQQTkRnPQXYRTQcQTRVRXYWSVeTW\TWXYX�kVYkT_QURSRSTdkVd �kVddanVY[ dUVd\VQRXVYcVdVTkdX\VRTN ZXRSXYRSTkVRkS\TYRnRSTWRQVRXQVcSXk WX�TQTdVRXYWVY[kQVRTQ _QT�PTYka[XWRQXUPRXYWRVRXWRXkW_Q\ RSTPcWRQTV\ kSVYYTdYTRZ QoWkYbWRQVXYVkRXeXRa _RST[QVXYVTYTRZ QoVY[_VYk\cdT]PYRXdRSTTVQda�TWcTQXVYpOXN�sN�STfMhh\[QcXYZVRTQdTeTd[PQXYRSTRX\TQTkQ[T[ RSTUa �acVYXW[TdRVXk[TcWXRWnSZTeTQn\VacRTYRXVddaQTmTkRV[TkdXYTXYRSTVUPY[VYkTVY[WRVUXdXRa _ZVbRTQ dUVddaVRRST\VQRXVYWPQ_VkTV_RTQVdVRTb� VkSXVY dUVdkdX\VRT cRX\P\ p�QZXYTRVdNn �JhhM OVWWTRRVY[�TV[nJhh�snRSPSRSXW RSXWQT�PXQTW_PQRSTQRTWRXYN�XRSXY eTQVdd[QaXYRQTY[n RSTmPeXVdmZ ZXRSXY kVRkS\TYR UTk\T\VaSVeT XYbkQTVWXYdaTcST\TQVdQTcXW[XknVWRSTVeVXdVUXdXRa _dX�PX[ZVRTQ[TkQTVWT[N [T\ YWRQVRT[ RST�SXWRQVYWXRXYXW XY d[TQnSXSTdTeVb

RXYcVQRW_RST�acVYXW_VYk\cdT]nZSXkSVQTXYkXWT[UaYTQ\ QTdVRTbWRVTTQWXYVdkSVYYTdWN�SXdWRc QdakYWRQVXYT[nX_RST RSTU[a _ZVRTQ �acVYXW[TdRVWaWRT\_Q\T[XYZVWVYQRSbTQY kTVYnRSVR kkPcXT[RSTRc QVcSa_RSTT]XWRXYYQRSTQYcdVXYWnZTTWRX\VRTV[QcXYZVRTQdTeTd_Mhh\n_Q\ ZSVRXWYZgJMhh\XYTdTeVRXY Td aR gKhhh\N�TYkTnRST _RST _Q\�acVYXW_VY[TcWXRWQTkQ[TYeXQY\TYRW URS�VQW�kdXb\VRXk cRX\P\nVY[_Q\ VcTQX[[PQXY ZSXkSdX�PX[ZVRTQZVWUTXYYXY \ [X_aXYR cdVaV[TkQTVWXY QdTXY RST\VQRXVYdVY[bWkVcTN�YWP\\VQanRST�acVYXW_VYWT[X\TYRVQaWaWRT\ __TQWVYPRWRVY[XY ccQRPYXRaXYV_PRPQTQURXkT]cdQVRXY\XWWXYRRTWRRST RSTSacRSTWXW_ QdVQTWTVW kTVYWXY YQRSTQYcdVXYW_�VQW_Q\WT[X\TYRVQaQTkQ[WN�u���~}��w����ST WaWRT\�acVYXW_VY kYWXWRW _\PdRXcdTnXYRTQkYYTkRT[XYbeTQRT[kSVYYTdWVY[dUVRT_VYbU[XTWnZSXkST]RTY[ PR_Q\ RST�acVYXW�VddTW PRdTR �SQaWT cdVXYWNVY[XYR RST �dVYXRXV OQ\VYVdaWXW _ cVdVT\ QcSd anXRW ZTXYRTQcQTRRST�acVYXW_VYWaWbRT\ VWVYVYkXTYR[TdRV[TcWXRRSVR_Q\T[VRRST\VQXY_VWRVY[XY RST � VkSXVYU[a _ZVRTQXY dVRT QTVQda�TWcTQXVYTckSWN�STT]RTYR _RST RST[TdRV[TcWXRW\VoTW�acVYXW dVQTWRQTcQRT[[TdRVb_VYWaWRT\ WaWRT\Y _�VQWN�dT\TYRW RST[TdRVT]RTY[VR VY[dTVWR RST�qho\ YQRSTVWR _ �acVYXW�VddTW PRdTRn[TWkTY[Mhh\ XYTdTeVRXYN�SXW[ZYWdcTcQ QV[VRXY_RST[TdRV[TcWXRW� �Q_QkT[QTQTWWXY XWkYWXWRTYRZXRSRSTQTbRQTVR _VWRVY[XY U[a _ZVRTQVkQWWVRdTVWRRSXWSQX�YRVdVY[ VR VQTYReTQRXkVdT]RTYRN�ST_VY[TcWXRW �acVYXW Rc QVcSbXkVddakY�YT[nWP TWRXY RSVRRSTdkVdUVWXYZVW cTYR RST\PkSdVQTQbWkVdT�SQaWT�dVYXRXVRc QVcSXkUVWXYnVY[cWWXUdaV �VQWNWXYX�kVYRcVQR_RSTYQRSTQYcdVXYW_ �STWT[X\TYbRVQaWaWRT\RSTQT_QTcRTYRXVddaQTkQ[WRST � VkSXVYdVRT QTVQda�TWcTQXVYSXSWRVY[ WTV �SQaWT_VQTXYVd XY �dVYXRXVnVY[cbRTYRXVddaVYTeTYdVQTQWkVdTZVRTQU[aRSVR_Q\TQdakkPcXT[cVQRW _RST RSTRX\T RSTYQRSTQYdZdVY[WN a RSVR \ WR[XWRVd[TdRV[TcWXRWVR SV[�acVYXW UTTYT\cdVkT[nZVRTQdTeTdWSV[[QccT[UafMhh\N�SXWWP TWRWRSVR VRRST[TdRV_Q\VRXY�acVYXWWcVYYT[ RX\T kdX\VRTPYbV cTQX[[PQXYZSXkS�VQW�[TQZTYRWXYX�kVYRkSVYTN¡~¢��£}yx¤y{y����ST VYYa\ PWVPRSQWZ Pd[dXoTRRSVYo�Xk VoTQVY[VYQTeXTZTQ_QRSTXQRX\TdaVY[RSQPSQTeXTZWN�T QVRT_PddaVkoYZdT[TRST RST RSTWPccQR _ �¥�cVkTlTYkaVY[ �¥�kXTYkTVY[�TkSYd aOVkXdXRXTW�PYkXdp��O�s_QWPccQRXYWkXTYkTQTdVRXY R �]�VQW¦eTQdVY[XY WXRTWTdTkRXYVkRXeXbRXTWVY[�QVkT§VWQUXRTQcVQRXkXcVRXY WkXTYRXWRWeXVRST_ddZbXY QVYRW���©�hhiqMi©�VY[��©�hhJMqª©�p��§sn��©¥MhJK��©�VY[ ��©¦hhJKMM©� p«�jsn��©�hhiqKª©� p�On�¦ n�§n��b�sn��©¦hh�q�K©�p�On�¦ n�§sVY[ ����©�hhiq�K©�p�§sN ZVWcVQbRXVdda_PY[T[Ua�l�l�VQWjVRVlYVdaWXW QVYR��ª�ql�hL§N¡||y�xw¬¡u­�||}y{y���z®{��yzw�}�PccdT\TYRVQa\VRTQXVdQTdVRT[R RSXWVQRXkdTkVYUT_PY[ YbdXYTVRSRRcW�©©[XNQ©�hN�h�i©NTcWdNJh��NhrNhqhN°y±yzy�~y�l[dTQn«N Nn «NONn «Nn �Nn Tddn OVZ[Yn�NnjVeXWn �VQYTQn�N�Nn�T_RYb�VWSn �VQQXWYn�N�NnJh��N�acRSTWTW_QRST RST RSTQXXY _ �acVYXW_VYbWSVcT[[TcWXRVR T[T_RST�SQaWTTWkVQc\TYRn�VQW�XWXRV[TdRV²�kVQPWNSRRcW�©©[XNQ©�hN�h�i©NXkVQPWNJh��NhMNhJ�N

Page 17: Open Research Online › 56400 › 1 › The Hypanis Valles delta_ The last... · Open Research Online The Open University’s repository of research publications and other research

��������� ���� ���������������������������������������������

��� ����������������� ���������!�"#$�!%&"�%'$!�("(#)!$�$(�'!'�%�")%*'("%))$#+�*�+�!&#(����$("�)")%*���&&*%(#()����'*)��#(�%(%*+ �$��'

,-. /012345678290:;2<8=264/926782<>?@A76@7B7887<CDEEFGEHIJGGDKGLHMNOPQRSNTUVWVTXSYZT[V\VT]SSZ_PT\VaVTbcOPZcNNTMVdVWVTdQcN eNTfV[VTgcNccThViVTiecRT[VTaPPQTfVT,..jVaQeZcQklPNmPQRcNO lSNlPNmQcmeSNRRPlSNOcQk SnmPlomSNelclmepemkmYQSqrYmeZPeNmYPsPRmPQNYPZeRtYPQPSn\cQRV[V]PStYkRVUPRVTuacNPmRj.vT,.wvxy,.wzwVMNRcNT{VTiSe|PcqTXVT\cNrSOT}VTiP\Sq~elT�VTWcQmPQT[VTaSqPmTdVTXQSZcQmT]VTiqlcRTMVTfe_QeNrT[VoaVT]PNOQeNTMVT]SNOPmTfVT \cRRSNTicNrPpeNT�VT aVT\qQlYePT�VT\qRmcQOT[VdVT}PqqZT]VT,.jjV�mQcmerQctYkTZeNPQcSrkTcNOSQeoreNSnckPQPOOPtSRemReNReOPgPQ_klQcmPQT\cQRV�lcQqR,jjT,�xyx.-VYmmtR���OSeVSQr�j.Vj.jv��VelcQqRV,.j.V.�V.jjVfcZPT\VTfPQZcNTXVWVTfSqQPT\VWVT�eZ_PZcNT[VUVT,..zVgQcNRpPQRPMPSecNUeOrPR�gMUR�SN\cQRV]PSZSQtYSSrkj.jT�.xy�,.VYmmtR���OSeVSQr�j.Vj.jv��VrPSZSQtYV,..zV.xV.jjVfcQPQTXSNcOWVTfYcmmclYcQkcT[cNS aVT,.jzV�P�qPNlPRmQcmerQctYkSNcNPcQksPm\cQRV �tclPacNPmV �leVjwjT��yj.zVfcQSsT}V]VTfSklPT[V\VTWSRmcQOTdV\VTWQcOOSlTUVMVT]cQpeNT[VfVT�ceZSmST�VuVbVThq|ZeNTUV�VTUSOOkTXV[VT iVMVT�SOPQ_SZT ,...V�mcNOcQOe|eNrmYPNSZPNolcmqQPSn\cQmecNeZtclmlQcmPQP�PlmcZSQtYSSrePRV[V]PStYkRVUPRVj.wT,v�xxy,v�xzVYmmtR���OSeVSQr �,...�P..j,wz�j.Vj.,� VfYcmmclYcQkcT[VaVT ,..wVackPN_PQrTgVbVXVTicNrT�VWVTfSqQPT\VT XkNcZelQepPQlYcNNPRRqrrPRmc SNroepPO}SclYecNlQcmPQ cPSN\cQRV]PStYkRVUPRViPmmVx,VYmmtR���OSeVSQr�j.Vj.,��,..w]i.,,�-�VfceQTgVWVT\laYPQRSNT[V]VTj��-VM qpec ncNRcNOmYPeQNcmqQc OeRmeNlmeSNnQSZQepPQR_cRPOSN tQSlPRRPRT tQSlPRRPRTZSQtYSSrkTYkOQcqel RPOeZPNmcQk cNOnclePRcRRPZ_crPRV[V�POeZPNmVUPRVv-�xc�T-w.y-z�VfSkNmSNT�V{VTdPOZcNT�VWVT��qkQPRT�V�VTaQPmmkZcNTgVbVTfQ�lNPQT iV]VT[VTupcNRTUPPOkTUVWVT�mcQQTUVT [VUVTMQNSOT XQcPTXV\VTuNrPQmTaVMV[VT\Pm|rPQTMVuVT\emQSoncNSpT�VTgQSZ_cT[V�VTO��RmSNTWVT��NPTbVT]cRNcqmT�VTbcZcQcTXVhVT[cNPRTXV\VT\cQleceRTUViVT\cqQelPT�VT\eYPPpcT�VTgckSQT]V[VTgScQTUVT�YeNSYcQcTWVT,..,VXeRmQe_qmeSN RqQnclPSnYkOQSrPNeNmYPNPcQ Sn\cQR�PpeOPNlP Rq_onSQRqQnclPelPOPtSRemRV�lePNlP,��TzjyzwVfqQQTXV\VTfQqNSTfVWVTicNcrcNTaVXVT]c|PTiV�VT[cPrPQT�ViVT�ScQPTUV[VT�cNfqNgRPqNrT[Vo\VT fcSrcT�eNNPQ[QVT[VMVT �V\VT,..�V\PRSRlcP OPtQPRoQceRPOQeZReSNR�\UUXR�SNucQmY�cQPpePs SnmYPlYcQclmPQeRmelRTtQSlPRRPRTcNORtcomec OeRmQe_qmeSNRSncNcSrRnSQ\cQRVacNPmV�tclP�leVw�Tw��yw�vVYmmtR���OSeVSQr�j.Vj.jv��VtRRV,..zVjjV.jjVWcQOPNcRTfVgVT\SYQerTXVT]SqOrPTgVMVT,.jzVdqpecRmQcmerQctYkSnpcPk� RcmMPSeRXSQRcT\cQR�PpeOPNlPnSQ_cRPoPpP�qlmqcmeSNRlSNmQSPO_kcOSsNoRmQPcZscmPQ_SOkV]�Mfq Vjx.�xy-�T-z-y-�zVWcQQT\VbVTbPcOT[V�VT,.jwV\cQmecNRqQnclP�NPcQoRqQnclP eNpPNmSQk�scmPQ RSqQlPRTReNRT ,.j-]i.v,-v-VcNOlYcNrPRsemYmeZPV]PStYkRV iPmmV-,TUPRV YmmtR���OSeVSQr�j.Vj..,�,.j-]i.v,-v-VWcQQT\VbVTbPcOT[V�VT,..xV�lPcNR cNSN\cQR� cRRPRRZPNmSnmYPS_RPQpcmeSNcPpeOPNlPcNOtSRRe_PncmPV[V]PStYkRVUPRVTacNPmRj.zVYmmtR���OSeVSQr�j.Vj.,��,..,[u..j�vxVWYcZ_PQceNTuViVTg�QN�peRmTgVuVT�YPNT�VT\cq|TfVT�ceNrcT[VT,.jzVMNcmSZkSn\eRReRRetteXPmc lScRmcrQSsmYcNO eZtelcmeSNRemR nSQ QPRmSQcmeSNV�leVMOpV-VYmmtR���OSeVSQr�j.Vjj,v�RlecOpVccQ-�-.VWYcmcNcNmcpPmTaYceQSmTicZ_T\elYcPaVT,.j-V�POeZPNmmQcNRtSQmcNOmStSrQctYelPpSqmeSNSnclSqtPOQepPQcNOQepPQtqZPRkRmPZ�cNP�tPQeZPNmccNONqoZPQelcRmqOkV[V]PStYkRVUPRVTucQmY�qQnVjj�Tj,vxyj,z,VYmmtR���OSeVSQr�j.Vj..,�,.jx[d..,zj.VWYcmcNcNmcpPmTaYceQSmTicZ_T\elYcPaVT}emmQSqPQT[PnnQPkMVT,.j,VfclscmPQlSNomQSRSncpqReSNSlcmeSNSNOPmcRV]PStYkRVUPRViPmmVx�VYmmtR���OSeVSQr�j.Vj.,��,.jj]i.w.j��VWYQeRmPNRPNTaVT[cSRkTfVThePnnPQTbVT\ceNT\VT\l�sPPNTbVT}PcRSNThVT\PYcT]VT�epPQZcNT�VTdPQQkT�VTWcteNrPQT\VT \VTUcpeNPT ,..-VgYPgYPQZcuZeRoReSN�ZcreNr�kRmPZ �gbu\��� �tclPnSQmYP\cQR,..j�OkRRPkZeRReSNV �leVUPpVjj.Tzwyjx.VYmmtR���OSeVSQr�j.Vj.,x�_�Rtcl Vjvx.wV.....,j..z V�-VWemQSNTUV�VT\cNrcT\VTbPZeNrsckTXV[VT,.jzVgeZeNrSn SNSlPcNR \cQRnQSZRYSQPoeNPOPnSQZcmeSNV}cmqQPwwwTv-xVWennSQOT�V\VTacQPQTgV[VT,..jVgYP YkOQSRtYPQP�PpSqmeSNSnmYP\cQmecN eZtelcomeSNRnSQmYPncmPSnctQeZSQOecSlPcNcNOmYPlqQQPNmRmcmPSnmYPNSQmYPQNtceNRV�lcQqRjw-T-.y��VYmmtR���OSe �elcQV,..jVvv�jVSQr�j.Vj..v VWSRmcQOTdVT�~�SqQN~TMVThPnSqNThVTWennSQOT�VTicperNPT aePmQST fSqPkTdVTXe �VT �VT,.j�V\SOPeNr PZtclPZPNmmRqNcZetQStcrcmeSNcNOmYP SnmYqZ_tQeNmmPQoQceNeNcNPcQk\cQRSlPcNV[V]PStYkRVUPRVTacNPmRj,,Tvxxyv-�VYmmtR���OSeVSQr�j.Vj..,�,.jv[u..w,x.VWQcOOSlTUVMVT\c�sPTgVMVTbSscQOTMVXVTj���VWQcmPQZSQtYSZPmQkcNOZSOe�olcmeSNeNmYP�eNqR�c_cPqRcNO\cQrcQemenPQ�eNqRQPreSNRSn\cQRV[V]PStYkRVUPRVTacNPmRj.,Tjxx,jyjxx-.VYmmtR���OSeVSQr�j.Vj.,����[u.j.z-VWqPpcR\cQm�NP|T[ViVTWc_QPQca~QP|TiVT\cQlqPST \cQ|SMVTMQ_q~RWc|STaVT WcQoteST\VTfPZqNmTdVT,.j.Vu�YqZPOlYcNNPRcNORmSNPNPmsSQRsemYeN�qpecncNOPtSRemRnQSZmYP�erSo\eSlPNP �SqmYoPcRmWcRtPdSQZcmeSNT u_QSfcReN�}SQmYoPcRm�tceN�V�POeZPNmSSrkw��j�Tjv,yjz�VYmmtR���OSeVSQr�j.Vjjjj��Vjxvwox.�jV,..� V�V.j.�v VXcpeRT[V\VTfcZPT\VT]QeNOQSOTaV\VT�eecZRTUV\VuVT]qtmcT�VT,.jvVu�mPNRepP}SclYecN�qpecRkRmPZReN eZtelcmeSNRMQc_ecgPQQc� nSQPcQk\cQmecNleZcmPV]PSSrk--�j.�Tz-�yzw.VXeMlYePT]VTbkNPTfV\VT,.j.VMNlePNmSlPcNSN\cQRRqttSQmPO_krS_cOeRmQeo_qmeSNSnOPmcRcNOpcPkRV}cmV]PSRleVxT-w�y-vxV

XefecRPTUVMVTieZckPTMVfVT�lYPeNrQSRRT[V�VTdeRlYPQT�V�VTicZ_T\VaVT,.jxVXPmcelOPtSRemRcmMPSeRXSQRc�RPOeZPNmcQkPpeOPNlPnSQcRmcNOeNr_SOkSnscmPQSNmYPNSQmYPQNtceNRSn\cQRV[V]PStYkRVUPRVTacNPmRjjzTj,zwyjx.,VYmmtR���OSeVSQr�j.Vj..,��rQPV,.j..VuRQeT,.jvVbSsscmPQRYPOsSQRV�cmPQRYPO�SQRVdcRRPmmTWV�VTbPcOT[V�VT,..zV lSNogYPmeZeNrSnZcQmecNpcPkNPmsSQ clmepemk�RmQceNmRnQSZ _qnnPQPOlQcmPQlSqNmeNrV�lcQqRj�wTvjyz�VYmmtR���OSeVSQr�j.Vj.jv��VelcQqRV,..�Vj,V..�V]cNmeT{VTWYqT�VTicZ_T\VaVT}emmQSqPQT[VMVT ZSQtYSOkoacQPQT]VT,.j-VgPRmeNrNcZellSNmQSRSNmYP SlcmeSNcNOnQP�qPNlkSnQepPQcpqReSNRSNncNRpPQoRqROPmcR�bqcNrYP��PSsUepPQ�TWYeNcV]PStYkRVUPRViPmmV-jT�zz,y�z�.VYmmtR���OSeVSQr�j.Vj..,�,.j-]i.vj�jzV]e_eNrT\VTUqRmTfVTj��.VUe__SNRcNORmSNPR aPNNRkpcNecNeNmYP �cOOPNRWSpPnSQZcmeSNT�kONPkfcReNTMmcNmelWcNcOc�mYPeN�qPNlPSnReelPSqROqQelQqRmRSNlYcNNPo_SOkrPSZPmQkV�POeZPNmSSrkx�T-wyvvVYmmtR���OSeVSQr�j.Vjjjj��Vjxvwox.�jVj��.Vm_.j�z,V�V]SqOrPTgVMVT\eePNTUVuVTbPcOT[V�VT [VdVTdcRRPmmT\qRmcQOT WV�VT,.j�V�POeZPNmSSroelcPpeOPNlPnSQcOPmcelSQereNSnmYPsPRmPQNncNOPtSRemeN[P|PQSlQcmPQT\cQRcNOeZtelcmeSNR �leVnSQnqmqQP acNPmVP�tSQcmeSNVucQmY iPmmV-wzTxw�yxvwVYmmtR���OSeVSQr VPtR�j.Vj.jv�� V,.jv V.wvVj. V]SqOrPTgVMVT\qRmcQOT[VdVT [V�VTdcRRPmmTbPcOT WV�VT�eRPZcNT MRRPRReNr�V\VT,.jwVmYP mYP mYPZeNPQcSrkSn scmPQRYPOcNOncNOPtSRemRSn [P|PQSlQcmPQtcPScPRkRmPZT\cQRV[V]PStYkRVUPRVTacNPmRj,.T��wyz.zVYmmtR���OSeVSQr�j.Vj..,�,.j-[u..-�z,V]QSm|eNrPQT[VaVT]qtmcT \ceNT�VT \VWVT �lYeP_PQTUq_eNTXV\VT [VT�eP_clYT �qZNPQThVTXV�VTPmcVT,.jwVXPtSRemeSNTP�YqZcmeSNTcNOtcPSleZcmP cNlePNmSncN cPOPtSRemT]cPlQcmPQT\cQRV�lePNlPxw.�v,w��Tccl�w�wV]qtmcT�VTj���VbeZcckcN cNOOQceNcrPtcmmPQNR mYPSQereNSn�qpec ZPrcncNReNmYP]cNrPRnSQPcNO jjyj-V_cReNV]PSSrk,wT YmmtR���OSeVSQr�j.Vjjx.�..�jo�vjx�j����.,w�..jj�bXaMg��,VxVW��,VbcQmZcNNT�VhVT,..wV\cQmecNlQcmPQeNrz�eRSlYQSNQP�NPZPNmcNOmYPlYQSNSSrkSn\cQRV�lcQqRj�-T,�-yx,.VbcQmZcNNT�VhVT}PqqZT]VT,..jVWQcmPQeNrlYQSNSSrkcNOmYPPpSqmeSNSn\cQRV�tclP�leVUPpV�vTjvwyj�-VYmmtR���OSeVSQr�j.Vj.,x�c�j.jj�-w,,,.j.Vbcq_PQTuVT]seNNPQThVThPeNYcNRT\VTUPeRRTXVTXeMlYePT]VT�QeT]Vo]VT�lYSmPNTdVT\cQeNcNrPeTiVT[cqZcNNTUVT ,..�V}PqqZT]VT �POeZPNmcQk eNOPtSRemR �cNmYPgPQQc�eZtelcmeSNR cNlePNmleZcmPnSQmYP SN\cQRV�N�uqQV\cQR�leVu�tSQVWSNnVu\�uWVacNPm�tclP�leVw�T�--y�w�VYmmtR���OSeVSQr�j.Vj.jv��VtRRV,..zV.vV..�Vbcq_PQTuVTacm|TgVTUPeRRTXVTiPXPemTiVThPeNYcNRT\V]VT\cQQcT�VMVTOPbccRTgVTWcQ_SNNPcqT cNOaVT,.jxV nSQZcmeSNMRkNlYQSNSqR SnbPRtPQecN MZc|SNecNocrPOOPmcRSN\cQRcNOeZtelcmeSNRnSQleZcmPV[V]PStYkRVUPRVTacNPmRjjzTjw,�yjw--VYmmtR���OSeVSQr�j.Vj..,��rQPV,.j.�VbkNPTfV\VTfPclYT\VTbSPT\VUVgVT,.j.V�tOcmPOrS_c ZctSn\cQmecNpcoPkNPmsSQRcNOeZtelcmeSNRnSQleZcmPcNOYkOQSSreltQSlPRRPRV[V]PStYkRVUPRVTacNPmRjjwVYmmtR���OSeVSQr�j.Vj.,��,..�[u..xw-zV�QseNT�VTUSRRZcNTaVTWQcOOSlTUVMVTbSscQOTMVXVT,..wV�NmPQeSQlYcNNPReN\cQomecNpcPkNPmsSQR�OeRlYcQrPcNOQqNSnntQSOqlmeSNV]PSSrkxxT-z�y-�,VYmmtR���OSeVSQr�j.Vjjx.�],jxxxVjV�QseNTUVaVT [VMVT acPSYkOQSSrkiPseRThV�VTbSscQOTMVXVT]QcNmT ,.jwV Snu_PQoRscOPlQcmPQT acNPmV ]PSo\cQRV�N� ]PSZSQtYSVaQSlV-wmYMNNqVfeNrYcZmVZSQtYSV�kZtVbPOj,yj-�PtmV,.j-ThNS�pVTgPNNVT��MV]PSZSQtYSSrk,-.Tzxyj.jVYmmtR���OSeVSQr�j.Vj.jv V,.j- V.j,��VrPSZSQtY Vj. V�QseNTUVaVTgcNccThViVTUS__eNRT�V[VT,.jxVXeRmQe_qmeSNSnucQkT\eOOPTcNOicmP}SclYecNlQcmPQPORqQnclPReN eZtelcmeSNRmYP\cQmecNYerYcNOR� nSQQPRqQoncleNrPpPNmRcNOtQSlPRRPRV[V]PStYkRVUPRVTacNPmRjjzT,�zy,�jVYmmtR���OSeVSQr�j.Vj..,��rQPV,..wxV�pcNSpTfVT}PqqZT]VT�crNPQTUVT,..jV�e|PonQP�qPNlkOeRmQe_qmeSNRSntcNPomcQkeZtclmlQcmPQRcNOcRmPQSeORV�N�WSeReSNcaQSlPRRPReNmYP�ScQ�kRmPZV�tQeNrPQTttVjyx-VheQTUViVTbSseNrmSNohQcqRTuVTUSRePT\VUVTMNOPQRSNT[VMVTMQlYeNcTfVMVTfPlPQThV[VT XV\VTWSSTXVMVT]cqR|cT ]PeRRPQTaVuVTbcQPTgV\VTbSZ_PQrT�V\VThPR|mYPokeTiVaVTUPOOeNrTfViVTXPcZPQPT�VMVT]ccrYPQT WYctPTXVT [VXVTuecRSNTuV\VTheNrTUVT\lusPNTMV�VT,..zV ZctteNr�mQcYerYQPRSqmeSN mStSrQctYel Sn\cQRsemY\U�beU��uRmPQPSeZcrPR�ZPmPQoRlcPRStPR lcNOeOcmPaYSPNe�SncNOeNrRemPRV[V]PStYkRVUPRVTacNPmRjjxTu..M,-VYmmtR���OSeVSQr�j.Vj.,��,..�[u..x...VhNcOPT[VTbcq_PQTuVTacm|T heNlYTgVTiPXPemTiVT hVT,.j�VXPmcePOrPSSrelcZctoteNrSnmYP�qpecOPtSRemReN\crSNrlQcmPQT�cNmYPgPQQcT\cQRV uqQStPcN�N�acNPmcQk�lePNlPWSNrQPRRTpSVjjVhNPeRRTgVT\elYcPT]V]VTacm|TgVT�cmPQT�VbV]VT,.jwVMrPOPmPQZeNcmeSNSneNPcQRqQnclPnPcmqQPRqReNrmYPfqnnPQPOWQcmPQWSqNmeNrcttQSclYylcRPRmqOePRSnmYP�eQPNqZ cNOdSQmqNcdSRRcPrQc_PNRkRmPZRSN\cQRV�lcQqR,w.Txz-yx�-VYmmtR���OSeVSQr�j.Vj.jv V,.j-��VelcQqR Vj,V..zVhQccTuVUVTpcNXe�T\VTaSRmZcT]VThPeNYcNRT\V]VT,..zV\cQmecNRmPttPOoOPmcnSQZcmeSN_kQcteO QPPcRPVscmPQ }cmqQP-wjT��xy��vVYmmtR���OSeVSQr�j.Vj.xz�NcmqQP.vvjwV\ceNT\VWVTfP ���T[VdVTWcNmSQTfVMVTWcteNrPQT WcpeNT\VMVT �V\VTWcNlkTUVgVTuOrPmmThV�VTuOscQORTiVTbc_PQPTUV\VT[cZPRTaVfVTiPPT�V�VTUcpeNPT\VMVTgYSZcRTaVWVT�SnnT\V[VT,..�VWSNmP�mlcZPQceNpPRmercmeSNSN_ScQOmYP\cQR

Page 18: Open Research Online › 56400 › 1 › The Hypanis Valles delta_ The last... · Open Research Online The Open University’s repository of research publications and other research

��������� ���� ���������������������������������������������

��� ����������������� ���������!�"#$�!%&"�%'$!�("(#)!$�$(�'!'�%�")%*'("%))$#+�*�+�!&#(����$("�)")%*���&&*%(#()����'*)��#(�%(%*+ �'��'

,-./012345/6-78/95:/31,6/345/9;<=>43=4?45549@ABBCDBEFGDDAHDIE JKLMNOPQQRSTTRQONPMUSVNMW XNPYZ[TW\W ]NTWLLJ _abKWZVVYTcddePSWPMfdLWLJgdJ hiN JjjWkO_lNQ mWbW_nSRTPQ_WkWoNMfTVMPp\WqW rRQTNQoMSefNTsWtW uW\WvNnRpNMNqWmWXMRQV\WmW wW ]WwWXxnSOyzWuW {W_WrNMyNQZP|| {NT}VZNn[S {SMy kNnnPQkWtWb~x[MNTbWqWtZPpRTsWqNSV}uWkWJ �WkRMTMNOPQQRSTTRQONPMUSVNM�TZSfZ \WMNTPnxVSPQ SpRfSQf �rS]�b_�WTOSNQONN�YNMSpNQV XNPYZ[TW]NTWLLJ_abJWZVVYTcddePSWPMfdLWLJgdJ aiN JhaWkSOZRNnXWXWJL�W�nRQNVRM[TxM|RONeRVSQf|MPpOMRVNMTS}N�|MN~xNQO[eSTVMSUxVSPQpNRTxMNpNQVTcpxnVSYnN eS||NMNQVSRnMNTxM|ROSQfNYSTPeNTRQe STPOZMPQ�VVSQfW�ORMxTJJhjja�jgWZVVYTcddePSWPMfdLWLLh WJL�diWSORMxT W�W KWkPPMN\WkWrPlRMemWvWvSNVMSOZqW_WbOZNQy�WkWJ �WkRMVSRQnR[NMNe�x�SRneNYPTSVTcSpYnSORVSPQT OnSpRVN|PMsPROZSRQ TONQRMSPTWXNPYZ[TW]NTWwNVVW�WZVVYTcddePSWPMfdLWLJgdJ �XwLg JWsNnTPQvWkWXMNNnN[]WLgggWXNPnPf[ RQeP|�RQVZNtNMMRPxV�PlOZRQQNnT VZNkRMT�RVZ�QeNMnRQeSQfTSVNW\WXNPYZ[TW]NTW�nRQNVTLK jha��jhhgWZVVYTcddePSWPMfdLWLJgdgj\_Lg W�RSQ uW�WunRMyN\WvWmWtZPpRTkWJ �W�Q�NMTSPQ �QcP| PQMNnSN| kRMTW vNNY�pYROVkSTTSPQuPpNVg�tNpYNnL �RMVJW�ORMxTLg �J�K�j�KgLWZVVYTcddePSWPMfdLWLLhdiWSORMxTWJ �W�WL�W�RSQuW�W�SnSNMuWvWLggaW�Q�NMTSPQP| P|MNnSN|�ROPpYPQNQV nRQeTORYNN�PnxVSPQWXNPpPMYZPnPf[LJLaL�LhaWZVVYTcddePSWPMfdLWLLhdLhg�aaa��gK�`jK�aW�RMyNMNVRnWLgg�WuPRTVRnfNPpPMYZPnPf[P|VZNkRMVSRQQPMVZNMQYnRSQTW\WXNP�YZ[TW]NTW�nRQNVTgj�_h�LLhL�LL�jWZVVYTcddePSWPMfdLWLJgdg�\_ hLjW�nRV}tWrRxUNM_WwN zRQvNSVwW XRTTNnVbW{SQOZ {WkReTNQ kWoW]PTNQUNMfrW P|JLKWwRQeSQfRVVZNVNMpSQxT bRUMSQRzRnnSTcRYPVNQVSRnJJ kRMTMP�NMnRQeSQf �nRQNVRM[TSVNW�Qc_xMPYNRQ bOSNQONuPQfMNTT�PnWgW]RpSMN}]WkWuMReePOy ]WmWJLjWtZNfNPnPfSORnRQeOnSpRVPnPfSORnORTN|PMRlRMpNMRQelNVVNMNRMn[kRMTWsRVWXNPTOSWLL J��J��WZVVYTcddePSWPMfdLWL�jdTKLahL�Lj� g��gW]SONkWoNnn����\WXxYVRbWqRMQNMsWXPeeRMe{WmQeNMTPQ]WJL�WmeNVRSnNefNPnPfSOOZRMROVNMS}RVSPQP|_UNMTlRneNOMRVNMkRMTW�QVW bOSW\WkRMT _�YnPMWjLa�a�W]PeMSfxN}\WmW�W�RSM�QmWXWtRQRyR{WwW�RMMPOR ]WkWwSQRMNT �nRV}tW{PpRVTxXWkS[RpPVP \W oRyNMrW{RMfNn\WbW�RQ XxnSOyzWrSfxOZS{W zW]WXnSQNTsWJLhWtTxQRpSlR�NTN�VNQTS�Nn[MNTxM|RONeVZNTZPMNnSQNTP|RQNRMn[kRMVSRQPONRQWbOSW]NYWhJaLhWbRn�RVPMNkW]WuZMSTVNQTNQ�W]WJLKW zRTVSVRT�Q VZNVZNPMSfSQP| oPMNRnST�PM�pRVSPQSQuZM[TNRQemOSeRnSR�nRQSVSRN kRMTW\WXNPYZ[TW]NTW�nRQNVTLLgJK���JKahWZVVYTcddePSWPMfdLWL JdJLK\_ KhjJWbOZPQbWuWrNRe\WqW�RTTNVVuW�WJLJWmQP�NM�nnNenROxTVMSQNT[TVNpRQeYMPfMR�eRVSPQRneNnVRSQ\N}NMPOMRVNM sPROZSRQOnSpRVNW�nRQNVWkRMTcSpYnSORVSPQT|PMbYRONbOSWh�Jj�KaWZVVYTcddePSWPMfdLWLLh WJLJdiWYTT WJW �WbN|VPQ�sRTZ_W�RlePQ�WXxYVRbWoRnpNkWvR�ST\WXMSQeMPe�WbSeSMPYPxnPT�W�NMTZP�zWkxnnNM\W��WJLaWtZNr[YRQST�nx�SRn SQvNnVRSOb[TVNp �RQVZNtNMMRcm wRQeSQfuRQeSeRVN_�PkRMTJLj]P�NM bSVNWbSVVPQSwW�RPnRuWzPnnNMzWJLKWXNPpNVM[�Pl RQeTNeSpNQVVMRQTYPMVP|Rn�nx�SRneNYPTSVTSQexONeU[VPYPfMRYZSORnn[eMS�NQ�PlN�YRQTSPQTW\WbNeSpNQVW]NTWjKLJJ�L�aWZVVYTcddePSWPMfdLWJLLdiTMWJLKWLLW

bpSVZ vW_W�xUNMkWtW�MN[ rWzWXRM�SQ \WoW \WqWrNRe kxZnNpRQ vW�W�NV�VNQfSnnXWrW�ZSnnSYT]W\WbPnPpPQ bWuW�lRnn[rW\WoRQNMeVqWoWvx�UxM[tWuWXPnPpUNy kW�WwNpPSQN�WXWsNxpRQQ mZRMPQTPQXWmW]PlnRQeTvWvW�W�PMe�WXW��RQP�mWoW\PZQTPQuWwWkOXP�NMQ m|}Rn�W\WmUTZSMN\WoW ]WbWbxQ�WJ LW R|VNMkRMT�MUSVNM mnVSpNVNMcwRTNM N�YNMSpNQVTxppRM[ VZN�MTV[NRMP| P|fnPURnpRYYSQf kRMTW\WXNPYZ[TW]NTWLh J�hjg�J��JJWZVVYTcddePSWPMfdLWLJgdJ`iN L�hKWbVMRZnNMmWsWLga�W�xRQVSVRVS�NRQRn[TSTP|lRVNMTZNefNPpPMYZPnPf[W_PT�jgL��gJWZVVYTcddePS dt]�jS hY gL�WPMfdLWLJg WtRQRyR{WwWbySQQNM\WmWvPZp \W�MlSQ���]W�W{PnU_W\W�PMVN}}PuWkW�nRV}tWkSOZRNnXWXWrRMNtWkWJLKWXNPnPfSO XNPnPfSORnpRYP|kRMTc�WbW bxM�N[bOSNQVS�O�Q�NTVSfRVSPQTkRY�JgJ K�TORnNLcJ^ ` ` YRpYZnNV YWzRQvSiykW{nNSQZRQTkWXW�PTVpRXW{MRRn_WJLJWuPQVMRTVSQfpPMYZPe[�QRpSOTSQRnnx�SRn|RQTRQe|RQeNnVRTcN||NOVP|VZNePlQTVMNRp UPxQeRM[WbNeSpNQVPnPf[agJLJa�JLKaWzRQvSiykW�PTVpRXW{nNSQZRQTkWXWJ gWmxVPO[OnSOUNZR�SPxMP||RQeNnVRTcRQRQRnPfxNN�YNMSpNQVRnTVxe[WbNeSpNQVPnPf[ahLahg�LajgWzSnnRQxN�RXWwWkxppR kW\WsP�Ry ]W_W{�x� rW�WrRMVPfZ �W_QOMNQR} tWtPyxQRfRmW mW{ZR[RV bpSVZ kWvWJLaWbVMPQflRVNMSTPVPYSORQPpRnSNTSQVZNpRMVSRQRVpPTYZNMNcYMPUSQf bOSNQON�KjOxMMNQV MNTNM�PSMTWRQeRQOSNQVJLjWZVVYTcddePSWPMf dTOSNQONdLWLLJh WRRR�h�WqRMQNMsWrWXxYVRbWuRnN|�WXMSQeMPe�WoPnnsWXPeeRMe {WJLaWkSQSpxpN||NOVS�NRMNR|PMZSfZMNTPnxVSPQOMRVNMOPxQVSQfP|pRMVSRQVNMMRSQTW�ORMxTJKaLgj�JKWqSnnSRpT]WkW_W�MlSQ���]W�W \W]WJ gW�SpUNnpRQ _�RnxRVSPQP|YRnNPZ[eMP�nPfSOpPeNnT|PMVNMMNTVMSRnSQ�NMVNeOZRQQNnTcSpYnSORVSPQT RYYnSORVSPQ|PM VPpRMVSRQTSQxPxTMSefNTWXNPpPMYZPnPf[L�� ��LaWZVVYTcddePSWPMfdLWLLhdiWfNPpPMYZWJ jWLJWLaWqSnTPQbWrPlRMemWkPPMN\WXMRQV\WJ �WXNPpPMYZSORQeTVMRVSfMRYZSORQRn�[TSTP|uMRVNMtNMU[RQenR[NMNeeNYPTSVTQPMVZP|rNnnRTURTSQkRMTW\WXNPYZ[TW]NTW�nRQNVTLLJWZVVYTcddePSWPMfdLWLJgdJ h\_ Jj�WqPMeTlPMVZ]WvW{NMUNMwW�SNMMNZxpUNMV]WtW \WqW uPp��PMfNV�WrNRe JLaWYRMSTPQP|�lRMpRQelNV�RQe�OPneRQeSO[�TONQRMSPT|PMNRMn[kRMTSQR��vOnSpRVN RQe RQepPeNnclRMp lNV�TWOPne SO[NRMn[kRMTW\WXNPYZ[TW]NTW�nRQNVTLJ^ WLJL�LJLgWZVVYTcddePSWPMfdLWL JdJLa\_ K�j��RySmWbW�RSQuW�W_efNVV{WbWXSNfNQfROy]WJLjW�Q�NMVNeTVMNRpOZRQQNnTSQVZNqNTVNMQvNTNMVP|_f[YVcT[QNMfSTVSOMNpPVN�NnePUTNM�RVSPQT nRUPMR�RQeVPM[RQRn[TSTPQ_RMVZlSVZRYYnSORVSPQTVPkRMTW�ORMxT�g La�LJKWZVVYTcddePSWPMfdLWLLhdiWSORMxTWJLjW�W LW�NQfrW�Zx �W�Zx ]WJL�WsNlSQTSfZVTSQVPTNSTpSOTVMRVSfMRYZ[P|TZRnnPl�lRVNMYMPfMReRVSPQRnTN~xNQONTcTxUTNSTpSOOnSQP|PMpTW�QVNMYMNVWLbm�a�bmaLWZVVYTcddePSWPMfdLWLLgd�st�JL�� L�WLW�NQf rW�Zx�W�Zx]W�ZRQf �WJLJWXxSeNnSQNT|PMTNSTpSOTNeSpNQVPnPfSOTVxe[SQQPQ�pRMSQNYPTVMS|VURTSQTW�NVW_�YnPMWvN�W�gJga��KWZVVYTcddePSWPMfdLWLLhdbLj�h��jK�LJ�h Ka��W