Today Antarctica, Tomorrow Europa: Testing Broadband Seismometers in Icy Earthly Analogs
Session: InSight Seismology on Mars: Results From the First (Earth) Year of Data and Prospects for the Futur
Type: Oral
Date: 4/28/2020
Time: 11:15 AM
Room: 115
Description:
Given the success of the InSight mission, we look eagerly to the future of planetary seismology on a potential future target: Europa. This moon of Jupiter has a kilometers-thick ice shell atop a potentially habitable ocean. In Chaos terrains, hectic fracturing patterns suggest interaction between the ice surface and shallow subsurface water -- which may contain chemical signs of life in the ocean below. Pursuant to the goal of detecting biosignatures, the 2017 Lander Science Definition Team recommended a seismometer to: (1) measure the thickness of the ice shell and detect subsurface water, (2) determine the depth of Europa's ocean and (3) characterize internal structure.
In preparation for a future Europa Seismic Package, testing of a prospective broadband instrument has been carried out in the most analogous environment on earth: Antarctica. Following testing on the glaciated flanks of Mt. Baker in Washington, we deployed a set of two polar-rated Trillium Compact posthole seismometers at the Kamb Ice Stream at the edge of the Ross Ice Shelf. Here, 650 m thick ice is fractured in "pseudo-chaos" geometry. Instruments were configured 10 m apart and 1 m apart, to simulate a lander with 2 sensors, near the surface expression of a basal fracture. Each configuration was tested for 1 week in December 2019. Likely seismic sources are tidal cracking, nearby basal slip events, tectonic earthquakes and cultural noise from the scientific camp. We hope to obtain estimates of ice thickness and seismic velocity from reflections of impulsive sources and longer-period waves in the ice sheet. This can be compared against radar and seismic lines from this location. By using two stations, an evaluation can be made of the effect of the nearby fracture on the propagation of energy from varying azimuths. These results will refine our understanding of both the current capabilities and likely requirements of an instrument making the journey to Jupiter, as well as better document the conditions of the Kamb Ice Stream.
Presenting Author: Tiegan E. Hobbs
Authors
Tiegan E Hobbs tiegan.hobbs@canada.ca Natural Resources Canada, Vancouver, British Columbia, Canada Presenting Author
Corresponding Author
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Kynan H G Hughson khughson7@gatech.edu Georgia Institute of Technology, Atlanta, Georgia, United States |
Enrica S Quartini equartini@gatech.edu Georgia Institute of Technology, Atlanta, Georgia, United States |
Britney E Schmidt britneys@eas.gatech.edu Georgia Institute of Technology, Atlanta, Georgia, United States |
Mark P Panning mark.p.panning@jpl.nasa.gov Jet Propulsion Laboratory, Pasadena, California, United States |
Peter M Washam pwasham3@gatech.edu Georgia Institute of Technology, Atlanta, Georgia, United States |
Daniel J G Dichek ddichek@gatech.edu Georgia Institute of Technology, Atlanta, Georgia, United States |
Benjamin C Hurwitz bhurwitz@gatech.edu Georgia Institute of Technology, Atlanta, Georgia, United States |
Justin D Lawrence jlawrence@gatech.edu Georgia Institute of Technology, Atlanta, Georgia, United States |
Christina L Hulbe christina.hulbe@otago.ac.nz University of Otago, Dunedin, , New Zealand |
Huw J Horgan huw.horgan@vuw.ac.nz Victoria University of Wellington, Wellington, , New Zealand |
Today Antarctica, Tomorrow Europa: Testing Broadband Seismometers in Icy Earthly Analogs
Category
Insight Seismology on Mars: Results From the First (Earth) Year of Data and Prospects for the Future