Search Help
Global Change Master Directory (GCMD)
Antarctic Cretaceous-Cenozoic Climate, Glaciation, and Tectonics: Site surveys for drilling from the edge of the Ross Ice Shelf
Entry ID: NSF-ANT00-87392


Summary
Abstract: This award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, supports a collaborative research program in marine geology and geophysics in the southern central and eastern Ross Sea. The project will conduct sites surveys for drilling from the Ross Ice Shelf into the seafloor beneath it. Many of the outstanding problems concerning the evolution of the East and West Antarctic Ice Sheets, Antarctic climate, global sea level, and the tectonic history of the West Antarctic Rift System can be addressed by drilling into the seafloor of the Ross Sea. Climate data for Cretaceous and Early Cenozoic time are lacking for this sector of Antarctica. Climate questions include: Was there any ice in Late Cretaceous time? What was the Antarctic climate during the Paleocene-Eocene global warming? When was the Cenozoic onset of Antarctic glaciation, when did glaciers reach the coast and when did they advance out onto the margin? Was the Ross Sea shelf non-marine in Late Cretaceous time; when did it become marine? Tectonic questions include: What was the timing of the Cretaceous extension in the Ross Sea rift; where was it located? What is the basement composition and structure? Where are the time and space limits of the effects of Adare Trough spreading? Another drilling objective is to sample and date the sedimentary section bounding the mapped RSU6 unconformity in the Eastern Basin and Central Trough to resolve questions about its age and regional extent. Deep Sea Drilling Project (DSDP) Leg 28 completed sampling at four drill sites in the early 1970\'s but had low recovery and did not sample the Early Cenozoic. Other drilling has been restricted to the McMurdo Sound area of the western Ross Sea and results can be correlated into the Victoria Land Basin but not eastward across basement highs. Further, Early Cenozoic and Cretaceous rocks have not been sampled. A new opportunity is developing to drill from the Ross Ice Shelf. This is a successor program to the Cape Roberts Drilling Project. One overriding difficulty is the need for site surveys at drilling locations under the ice shelf. This project will overcome this impediment by conducting marine geophysical drill site surveys at the front of the Ross Ice Shelf in the Central Trough and Eastern Basin. The surveys will be conducted a kilometer or two north of the ice shelf front where recent calving events have resulted in a southerly position of the ice shelf edge. In several years the northward advance of the ice shelf will override the surveyed locations and drilling could be accomplished. Systems to be used include swath bathymetry, gravity, magnetics, chirp sonar, high resolution seismic profiling, and 48 fold seismics. Cores will be collected to obtain samples for geotechnical properties, to study sub-ice shelf modern sedimentary processes, and at locations where deeper section is exposed. This survey will include long profiles and detailed grids over potential drill sites. Survey lines will be tied to existing geophysical profiles and DSDP 270. A recent event that makes this plan timely is the calving of giant iceberg B-15 (in March, 2000) and others from the ice front in the eastern Ross Sea. This new calving event and one in 1987 have exposed 16,000 square kilometers of seafloor that had been covered by ice shelf for decades and is not explored. Newly exposed territory can now be mapped by modern geophysical methods. This project will map geological structure and stratigraphy below unconformity RSU6 farther south and east, study the place of Roosevelt Island in the Ross Sea rifting history, and determine subsidence history during Late Cenozoic time (post RSU6) in the far south and east. Finally the project will observe present day sedimentary processes beneath the ice shelf in the newly exposed areas.

Related URL
Link: View Related Information
Description: R/V Nathaniel B. Palmer, Cruise NBP0301
Marine Geoscience Data System (MGDS)


Link: View Related Information
Description: R/V Nathaniel B. Palmer, Cruise NBP0306
Marine Geoscience Data System (MGDS)


Link: View Related Information
Description: NSF Award Abstract #0087392

Geographic Coverage
 N: -75.9 S: -78.6  E: -159.1  W: 163.5

Data Set Citation
Version: Not provided


Temporal Coverage
Start Date: 2001-09-15
Stop Date: 2009-12-31


Location Keywords
CONTINENT > ANTARCTICA
GEOGRAPHIC REGION > POLAR


Science Keywords
OCEANS >MARINE GEOPHYSICS    [Definition]


Project
NSF/PLR >Division of Polar Programs, National Science Foundation    [Information]


Data Set Progress
COMPLETE


Data Center
United States Antarctic Program Data Center    [Information]
Data Center URL: http://www.usap-dc.org/

Data Center Personnel
Name: ROBERT A. ARKO
Email: info at usap-data.org
Contact Address:
Lamont-Doherty Earth Observatory
61 Route 9W
City: Palisades
Province or State: NY
Postal Code: 10964
Country: USA


Personnel
LOUIS BARTEK
Role: INVESTIGATOR
Email: bartek at email.unc.edu
Contact Address:
104 AIRPORT DR STE 2200
City: CHAPEL HILL
Province or State: NC
Postal Code: 27599
Country: US


Extended Metadata Properties
(Click to view more)

Creation and Review Dates
DIF Creation Date: 2013-03-14
Last DIF Revision Date: 2018-11-12



-->