Changing Earth’s surface

CHANGING EARTH’S SURFACEWater Erosion

Udden-Wentworth Scale

Sediments in Motion

Runoff Runoff: water that moves over Earth’s

surface. Runoff flows in a thin layer over land =

sheet erosion. Amount of runoff depends on:

Amount of rain in an area. Vegetation. Type of Soil. Shape of the land. How people use the land.

Effects of Runoff

Rills, Gullies, Streams and Rivers

Runoff, Rills, and Gullies

Erosion by Rivers Causes the Formation of:

Valleys Waterfalls Flood Plains Meanders Oxbow Lakes

Erosion of Rivers

Deposits by Rivers Anytime moving water slows down, it

drops, or deposits, some of the sediment.

Larger stones also quit rolling and sliding.

Creates these landforms: Alluvial Fans Deltas Soil on floodplains

Alluvial Fans A wide, sloping deposit of sediment

formed where a stream leaves a mountain range.

The deposit is shaped like a fan.

Deltas Sediment deposited where a river flows

into an ocean or lake builds up. Examples: Nile River (left) & Mississippi

River (right)

American River Delta in Sacramento, CA

Erosion and Sediment Load A river is a dynamic system.

Erosion and Sediment Load These factors affect how fast the river flows

and how much sediment it can erode: River’s slope

Increase in slope = water’s increase in speed Volume of flow

More water flowing in a river = increase in speed The shape of its streambed

River flowing in a strait line = water flows faster near the center of the river than its sides.

If a river curves = water moves fastest along the outside of the curve.

Erosion and Sediment Load

Erosion and Deposition Summary

Credits Schlumburger Website Retrieved on 3/12/12

http://www.google.com/imgres?q=picture+of+sediment+moving+in+water&hl=en&client=safari&rls=en&biw=1158&bih=702&tbm=isch&tbnid=cGZW6haL7-ve7M:&imgrefurl=http://www.glossary.oilfield.slb.com/DisplayImage.cfm%3FID%3D55&docid=Uzkq99EIoi0L6M&imgurl=http://www.glossary.oilfield.slb.com/files/OGL98036.jpg&w=393&h=400&ei=DlNeT6u1JqWuiQLP0YChBA&zoom=1&iact=hc&vpx=115&vpy=4&dur=244&hovh=226&hovw=223&tx=101&ty=117&sig=102853300329707996231&page=2&tbnh=165&tbnw=162&start=15&ndsp=20&ved=1t:429,r:10,s:15

Earth Science Australia retrieved on 3/12/12

http://www.google.com/imgres?q=picture+of+sedimentary+rock+in+moving+water&hl=en&client=safari&sa=X&rls=en&biw=1158&bih=702&tbm=isch&tbnid=41-qN5iKWb-JXM:&imgrefurl=http://earthsci.org/education/teacher/basicgeol/sed/sed.html&docid=PNekaZnN3EjcOM&imgurl=http://earthsci.org/mineral/rockmin/sed/clastics.gif&w=627&h=368&ei=W1ReT-fiFYHTiALfy5noBA&zoom=1&iact=hc&vpx=99&vpy=419&dur=7108&hovh=172&hovw=293&tx=194&ty=89&sig=102853300329707996231&page=2&tbnh=123&tbnw=210&start=15&ndsp=20&ved=1t:429,r:5,s:15

Creditshttp://www.google.com/imgres?q=picture+of+sediment+moving+in+water&start=136&hl=en&client=safari&rls=en&biw=1158&bih=702&tbm=isch&tbnid=La1Bxo5KOmHZQM:&imgrefurl=http://geologycafe.com/class/week9.html&docid=sBMQI_npMjdq7M&imgurl=http://geologycafe.com/images/stream_sediments.jpg&w=800&h=600&ei=EFVeT8rhAbTViAK-vZDfBA&zoom=1&iact=hc&vpx=860&vpy=282&dur=3630&hovh=194&hovw=259&tx=69&ty=80&sig=102853300329707996231&page=8&tbnh=151&tbnw=201&ndsp=20&ved=1t:429,r:4,s:136

Henry County Georgia retrieved on 3/13/12

http://www.google.com/imgres?q=picture+of+runoff&hl=en&client=safari&sa=X&rls=en&biw=1208&bih=691&tbm=isch&prmd=imvns&tbnid=gDG2L3H47Dqq3M:&imgrefurl=http://www.co.henry.ga.us/Stormwater/EffectsOfStormwaterRunoff.shtml&docid=hTY3kNciMaZVIM&imgurl=http://www.co.henry.ga.us/Stormwater/images/photo_RunoffEffects.jpg&w=457&h=336&ei=NmpfT9XOH-aiiQKwnvm7BA&zoom=1&iact=hc&vpx=314&vpy=305&dur=11&hovh=192&hovw=262&tx=129&ty=113&sig=102853300329707996231&page=2&tbnh=143&tbnw=195&start=15&ndsp=20&ved=1t:429,r:11,s:15

Virtual Geology Museum Retrieved on 3/13/12

http://www.google.com/imgres?q=picture+of+stream+erosion+and+deposition&hl=en&client=safari&rls=en&biw=1208&bih=691&tbm=isch&tbnid=0ZPFWRoQqYumUM:&imgrefurl=http://skywalker.cochise.edu/wellerr/VGM/opals-pals/058.htm&docid=Q-EmYyvDbY4izM&imgurl=http://skywalker.cochise.edu/wellerr/VGM/opals-pals/6opal058.jpg&w=640&h=451&ei=-9NfT4akDYaOiALa0LDFBA&zoom=1&iact=rc&dur=372&sig=102853300329707996231&page=1&tbnh=144&tbnw=204&start=0&ndsp=15&ved=1t:429,r:11,s:0&tx=71&ty=44