Inferred accumulation and thickness histories near the Ross/Amundsen divide, West Antarctica T. A. Neumann 1,2 , H. Conway 2 , S.F. Price 2 , E. D. Waddington 2 , D. L. Morse 3 1 Department of Geology, University of Vermont 2 Department of Earth and Space Science, University of Washington 3 Institute for Geophysics, University of Texas at Austin
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Inferred accumulation and thickness histories near the Ross/Amundsen divide, West Antarctica T. A. Neumann 1,2, H. Conway 2, S.F. Price 2, E. D. Waddington.
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Inferred accumulation and thickness histories near the Ross/Amundsen divide, West Antarctica
T. A. Neumann1,2, H. Conway2, S.F. Price2, E. D. Waddington2, D. L. Morse3
1Department of Geology, University of Vermont2Department of Earth and Space Science, University of Washington3Institute for Geophysics, University of Texas at Austin
Study Area
from Morse et al. (2002)
1.5 / 1.0 MHz data
5 MHz data
Profile lengths ~ 200km
flow divide7 MHz data
• mono-pulse transmitter (± 2000 V), 30 Hz
• resistively-loaded dipolar antennas
• digital oscilloscope records returned amplitude (mV)
• returns stacked (~ 1000) to generate single trace
• ground-based system
• Can cover (up to) 100 km day
• traces co-registered with GPS data.
Univ. of WA radar system
1.5 MHz data 1.0 MHz data
Byrd core site
‘Old Faithful’
Byrd core site
‘Old Faithful’
5 MHz data
Byrd core site
‘Old Faithful?’
Byrd core site
Converting picked radar layers to depth-age estimates:
1. Pick radar layers
2. Determine two-way travel time of layer at each site.
3. Convert two-way travel time to depth at sites.
used Herron-Langway (1980) model for (z); Looyenga’s equation.
4. Determine layer age using ice core depth-age data.
used data from Byrd cores [Hammer et al., 1994] and ITASE-00-1 [Dixon et al., 2004].