BEGIN:VCALENDAR PRODID:-//Microsoft Corporation//Outlook 16.0 MIMEDIR//EN VERSION:2.0 METHOD:PUBLISH X-MS-OLK-FORCEINSPECTOROPEN:TRUE BEGIN:VTIMEZONE TZID:Central Standard Time BEGIN:STANDARD DTSTART:16011104T020000 RRULE:FREQ=YEARLY;BYDAY=1SU;BYMONTH=11 TZOFFSETFROM:-0500 TZOFFSETTO:-0600 END:STANDARD BEGIN:DAYLIGHT DTSTART:16010311T020000 RRULE:FREQ=YEARLY;BYDAY=2SU;BYMONTH=3 TZOFFSETFROM:-0600 TZOFFSETTO:-0500 END:DAYLIGHT END:VTIMEZONE BEGIN:VEVENT CLASS:PUBLIC CREATED:20230119T175027Z DESCRIPTION:Speaker:\nSuzan van der Lee - Sarah Rebecca Roland Professor\, Department of Earth and Planetary Sciences\, Northwestern University\n\nTi tle:\nSubterranean dynamics in Earth and Mars\, inferred from big and smal l seismic data \n\nAbstract:\nVia expanded and densified networks of incre asingly advanced sensors\, seismology has become a science of big data ove r the past half century. Seismologists track hundreds of seismic waves per earthquake to locate their epicenters and infer their failure mechanisms. We model thousands of waveforms and combine tens of millions residual wav e propagation times to virtually 3D-print the Earth's interior structure. Sophisticated big-data analysis techniques extract subtle\, though vital d etails about the Earth's crust from scattered waves and ambient\, continuo usly recorded noise fields. This is in stark contrast to the data availabl e for fellow terrestrial planets. The only other terrestrial planet we hav e seismic recordings from is Mars. Through 2019-2022 a single broadband se ismometer was operational in Elysium Planitia on Mars\, as part of the InS ight mission\, and recorded dozens of marsquakes with similar shear-disloc ation failure mechanisms as earthquakes. However\, estimating epicenters a nd failure mechanisms for these marsquakes with waveform data from merely a single seismometer presented a new challenge in our current data-driven century. This presentation will show how we adapted small-data analysis me thods from the early days of digital seismology to be effective and robust analysis tools for Martian seismic data. Specifically we demonstrate how we estimate epicenters from relative arrival times of P and S waves and ho w we estimate failure mechanisms in terms of fault orientation and slip di rection from relative amplitudes of P and S waves. We will discuss the imp lications of our findings in terms of potential geologic\, tectonic\, and volcanic activity on Mars\, a planet much smaller\, colder and quieter tha n Earth. We conclude with a discussion on how we use algebraic geometry to improve uncertainty estimates for our inferences.\nSpeaker Bio:\n​Suzan van der Lee is the Sarah Rebecca Roland Professor in the Department of Eart h and Planetary Sciences at Northwestern University. She is also a NICO Co re Faculty member\, and a lead Professor with the Metropolitan Chicago Dat a-science Corps (MCDC) .\nEarthquak es are powerful evidence that the Earth is continuously reshaping. The sei smic signals emitted by earthquakes encrypt 1) important information about these powerful and sometimes destructive events\, and 2) intelligence abo ut the ongoing modification and dynamics of the Earth's interior. Professo r van der Lee applies data science to extract this intelligence from milli ons of records of seismic waves. She is particularly interested in develop ing and applying new methods of inference to extract relevant signals from seismic records and to image the Earth’s interior structure from hetero geneous data. She is a practiced observational seismologist and co-develop seismic and joint tomography methods\, including those using waveforms. \ nLocation:\nIn person: Chambers Hall \, 600 Foster Street\, Lower Level\nRemote option: https://nort hwestern.zoom.us/j/95501815086 \nPasscode: NICO23\nAbout the Speak er Series:\nWednesdays@NICO is a vibrant weekly seminar series focusing br oadly on the topics of complex systems and data science. It brings togethe r attendees ranging from graduate students to senior faculty who span all of the schools across Northwestern\, from applied math to sociology to bio logy and every discipline in-between. Please visit: https://bit.ly/WedatNI CO for information on future speakers.\n \n DTEND;TZID="Central Standard Time":20230125T130000 DTSTAMP:20230119T175027Z DTSTART;TZID="Central Standard Time":20230125T120000 LAST-MODIFIED:20230119T175027Z LOCATION:In person at Chambers Hall\, or remote via Zoom PRIORITY:5 SEQUENCE:0 SUMMARY;LANGUAGE=en-us:Wed@NICO\, 1/25\, Suzan van der Lee TRANSP:OPAQUE UID:040000008200E00074C5B7101A82E00800000000204F5BE84B2BD901000000000000000 01000000047AC036C689268409C2D2502CB5798AA X-ALT-DESC;FMTTYPE=text/html:

Speaker:

Suzan van der Lee - Sarah Rebec ca Roland Professor\, Department of Earth and Planetary Sciences\, Northwe stern University

Title:

Subterranean dynamics in Earth and Mars\, inferred from big and small seismic data \;
< br>Abstract:< /o:p>

Via expanded and densified networks of increasingly advanced sensors\, seismology has become a science of big data over the past half century. Seismologists track hundreds of seismic waves per earthquake to locate their epicenters and infer their failure me chanisms. We model thousands of waveforms and combine tens of millions res idual wave propagation times to virtually 3D-print the Earth's interior st ructure. Sophisticated big-data analysis techniques extract subtle\, thoug h vital details about the Earth's crust from scattered waves and ambient\, continuously recorded noise fields. This is in stark contrast to the data available for fellow terrestrial planets. The only other terrestrial plan et we have seismic recordings from is Mars. Through 2019-2022 a single bro adband seismometer was operational in Elysium Planitia on Mars\, as part o f the InSight mission\, and recorded dozens of < span class=SpellE>marsquakes with similar shear-dislocation failure mechanisms as earthquakes. However\, estimating epicenters and failure me chanisms for these marsquakes with waveform data from merely a single seismometer presented a new challenge in our current data-driven century. This presentation will show how we adapted small-dat a analysis methods from the early days of digital seismology to be effecti ve and robust analysis tools for Martian seismic data. Specifically we dem onstrate how we estimate epicenters from relative arrival times of P and S waves and how we estimate failure mechanisms in terms of fault orientatio n and slip direction from relative amplitudes of P and S waves. We will di scuss the implications of our findings in terms of potential geologic\, te ctonic\, and volcanic activity on Mars\, a planet much smaller\, colder an d quieter than Earth. We conclude with a discussion on how we use algebrai c geometry to improve uncertainty estimates for our inferences.

Speaker Bio:

Suzan van der Lee is the Sarah Rebecca Roland Professor in the Department of Ea rth and Planetary Sciences at Northwestern University. She is also a NICO Core Faculty member\, and a lead Professor with the Metropolitan Chicago Data-science Corps (MCDC).

Earthquakes are powerful evidence that the Earth is co ntinuously reshaping. The seismic signals emitted by earthquakes encrypt 1 ) important information about these powerful and sometimes destructive eve nts\, and 2) intelligence about the ongoing modification and dynamics of t he Earth's interior. Professor van der Lee applies data science to extract this intelligence from millions of records of seismic waves. She is parti cularly interested in developing and applying new methods of inference to extract relevant signals from seismic records and to image the Earth’s i nterior structure from heterogeneous data. She is a practiced observationa l seismologist and co-develop seismic and joint tomography methods\, inclu ding those using waveforms. \;

Location:

In person: Cham bers Hall\, 600 Foster Street\, Lower Level
Remote option: < a href="https://northwestern.zoom.us/j/95501815086?pwd=eE9EUTVlVlkrcTdOcjF vUUs1eFdCdz09">https://northwestern.zoom.us/j/95501815086
Passcode: NICO23

About the Speaker Series:

Wednesdays@NIC O is a vibrant weekly seminar series focusing broadly on the topics of complex systems and data science. It brings together attendees ranging from graduate students to senior faculty who span all of the schools acro ss Northwestern\, from applied math to sociology to biology and every disc ipline in-between. Please visit: https: //bit.ly/WedatNICO for information on future speakers.

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