Antarctic Earthquakes

Emma MyersIRIS Internship

Advisors: Dr. Rick Aster, CSUHarley Benz, USGS/NEIC

http://www.huffingtonpost.com/2013/12/09/antarctica-record-cold-_n_4415564.html

Antarctic Seismic Network

Guiding ResearchMarie 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● 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..”

• 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 CorrelationRepetitive 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 earthquakesEvents = 67, 5 templates neededEvents detected with SSD = 2777

Next StepsApply 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?

AcknowledgementsDr. Rick Aster, CSUNicole McMahon, CSU/NEICHarley Benz, USGS/NEICDan McNamara, USGS/NEICDave Ketchum, USGS/NEIC