Student Masters

RESOURCES:

Background:

How do you see under the ice? How do you see under the water? Sonar and seismic imaging allow researcher at both poles to look below the surface of the oceans and glacial ice. Using these methods researchers at the poles can map the topography of the Arctic and Antarctic seafloor and the Antarctic continent. (Researchers at the poles have been able to use this method to image through other matter.)

In Antarctica there are many research teams working aboard icebreakers like the Research Vessel Icebreaker Nathaniel Palmer. They study the recent tectonic history in the Antarctic Peninsula region and the major Antarctic seas. This research looks at how the Earth's crust is being deformed, destroyed and created at tectonic plate boundaries. To do this, they "see" the ocean floor using instruments that employ sound using a method called sonar. The sonar waves reflected back to the ship from the ocean floor are used to create images of the sea floor, making very detailed maps of surface features. Arctic and Antarctic researchers also examine the layering in Earth's crust below the sea floor, also using sound waves using a method called multichannel seismic imaging. Air canons produce sound waves at lower frequencies than sonar; they penetrate the ocean bottom and bounce off internal layers of the crust. As the returning sound waves are detected, they are used to build a picture of features below the sediments that we cannot see directly.

The research that I was involved in was conducted along the Antarctic Peninsula; an area that is tectonically active and complex both on the seafloor and in the upper crust. Several plates come together here. New sea floor is being created as plates slide past one another along strike-slip faults, and plates are being destroyed as they plunge into subduction zones. This is occurring in one very active location near Deception Island (an active volcano) and near the Antarctic Peninsula in an area called the Bransfield Straight. Understanding how the plates interact and what their history is will provide important information about how our Earth's crust changes through time. The detailed maps of geologic structures we are creating will be used to aid future researchers in the area.

Journal Articles

Distributed, Active Extension in Bransfield Basin, Antarctic Peninsula: Evidence from Multibeam Bathymetry

Discovery of new hydrothermal vent sites in Bransfield Strait, Antarctica

Hydrothermal and hydrographic surveys of the Bransfield Strait: Results from cruise NBP95-07

When the Earth Moves: Seafloor Spreading and Plate Tectonics 

Standards