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Science Picks -- USGS Seismology at the South Pole

Drillers at SPRESO

When the Bell Tolls: The South Pole location is unique in the world of seismology. Great earthquakes make the earth ring like a bell after being struck. Five miles from the South Pole, 1000 feet beneath the surface of the 10,000 foot ice cap, seismometers at the newest station in the Global Seismographic Network (GSN) are recording the quietest vibrations on the Earth, up to 4 times quieter than ever before observed. The South Pole location is unique in the world of seismology due to the quiet surroundings and lack of environmental "noise."

This new station, known by its 4-letter station code QSPA, is located at the new South Pole Remote Earth Science Observatory (SPRESO). Station infrastructure has been under construction for the past two Antarctic summer seasons, including the drilling of three 1000-foot, 12-inch diameter holes (in conjunction with the University of Wisconsin Ice Coring and Drilling Services) and the construction and burial of a 240 square foot heated electronics vault. USGS contracted personnel from Honeywell Technology Solutions, Inc accomplished the fieldwork.

Analysis of these oscillations reveals information about the earth's composition, especially when recorded at the spin axes of the globe where you can "hear" the earth ringing without the effects of the spinning globe. Since the North Pole is covered by a floating ice pack, the South Pole is the only place where one can record these oscillations with a seismometer that is well coupled to the continent below. Seismographs have been operating at the South Pole since the International Geophysical Year in 1957. Long-term data from high latitude seismograph stations such as the South Pole have contributed to evidence of the earth's solid inner core spinning at a slightly faster rate than the rest of the earth.

Antarctica is the continent with the smallest number of earthquakes. Since the new GSN station is so quiet, it will be possible to record much smaller Antarctic region earthquakes than ever before, leading to new insights into the evolution of the Antarctic Plate. The extremely low noise at QSPA GSN station makes it particularly valuable as the most sensitive southern hemisphere seismic station contributing data to the Comprehensive Nuclear Test Ban Treaty International Monitoring System.

Funded by the National Science Foundation, SPRESO is a collaboration between the Incorporated Research Institutions for Seismology (IRIS) consortium of universities and the USGS who will operate and maintain the station. IRIS has cooperated with the USGS since 1986 in the continuing effort to install and enhance the Global Seismograph Network.

Real-time USGS Earthquake Information

Setting up the drill rig	Core barrel adjustments	Anti-torque springs keep downhole drill motor from spinning	Core barrel assembly
Drill operations	Drilling pilot hole with core barrel	Drill control seat	Cutting head on Core barrel
Removing core from core barrel (1 trip per meter to get the ~4,000 year old ice)	Reamer cutting head for pilot hole expansion	Starting the 12" reamer (watch your feet)	Completed 12" diameter hole
Cable sled for SPRESO building (fiber, power and ground)	Installing SPRESO building with D7 Cat	SPRESO and sub-surface seismometer vault prior to burial	Towing seismometer to SPRESO
Seismometer transport to SPRESO	Borehole seismometer ready for 1000' foot drop	Jared Vineyard and deep borehole package ready for installation	Everyone asks this question anyway

For more information, contact: Carolyn Bell.