Transcript Antarctic Earthquakes

Antarctic
Earthquakes
http://www.huffingtonpost.com/2013/12/09/antarctica-record-cold-_n_4415564.html
Emma Myers
IRIS Internship
Advisors: Dr. Rick Aster, CSU
Harley Benz, USGS/NEIC
Antarctic Seismic Network
Guiding Research
Marie Byrd Land magma (Lough et al. 2013)
● “DLP” earthquake swarm
● Following volcanic trend
● Under topographic high
● Magma activity under the ice!
● Future eruption?
Lough et al 2013
Induced Icequakes (Peng et al. 2014)
● 2010 M8.8 in Chile create
“icequakes” in Antarctica
● Promotes motion
● Other glacial processes?
● Certain locations only?
● Relationships between earth and ice?
My Project
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Reassess previous research areas
Undetected earthquakes
Look at change in earthquakes over time and area
Support or expand area understanding
Improve program application
Opportunity to improve upon base Antarctic tectonic
and ice seismicity
So What?
“But no one lives there..”
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Improving techniques for areas beyond Antarctica for swarm
characterization (ex. Oklahoma)
Improving earthquake processing/predicting with this application; looking
at the development of seismicity in an area all the way down to small events
to understand possible future events, similar or more significant
The stations and data being used are very modern and could present a leap
in understanding tectonic and ice seismicity
Improve understanding of glacial events (induced icequakes, calving, rifting,
etc.) to look at the relationship between earth and ice as well as ice loss
Event Correlation
Repetitive process = repeated similar events = similar signals
Correlation: How similar is similar?
• Template creation
• Subspace detection, expanding the
comparison over a stream of data
Template Waveforms
The magic of linear algebra
A series of templates
Most significant chosen as necessary
representative templates (95%)
Subspace Detection - SSD
A “Subspace” =
a smaller portion that is able to describe the larger thing it is a part of
Sliding detection window, rapidly
comparing the templates chosen to the data
stream and correlating.
Picks out very small but very similar events
that were not detected before.
Similar Applications - OK
Nicole McMahon,
PhD student of Dr. Aster
Injection induced earthquakes
Events = 67, 5 templates needed
Events detected with SSD = 2777
Next Steps
Apply SSD techniques to Antarctica!
Marie Byrd Land – Have more events occurred than just these two swarms?
What can this tell us about the volcanic trend, direction and activity, through
time?
Icequakes – Can we more clearly link these events to being a byproduct of the
large event in Chile? Could we find other induced glacial earthquakes events?
Beyond – Can we find any other hot spots of seismic activity in West Antarctica
with these methods?
Acknowledgements
Dr. Rick Aster, CSU
Nicole McMahon, CSU/NEIC
Harley Benz, USGS/NEIC
Dan McNamara, USGS/NEIC
Dave Ketchum, USGS/NEIC