Geophysics Today Richard Allen *01, Karin Sigloch *08, Frederik Simons & Jeroen Tromp *92

Jeroen Tromp *92

Modern numerical methods and computers are transforming “forward” simulation capabilities

Daniel’s Coffee Cup Simulation

Open source software: SPECFEM3D “SESAME”

GPU CPU

GPU Computing

Princeton Earthquake Information"global.shakemovie.princeton.edu

Sumatra Earthquake April 11, 2012, M=8.7

resolution 17 s 5 h on 384 cores

Abundant, high-quality data are transforming “inversion” and “imaging” capabilities

“Adjoint” Tomography of Europe

earthquakes stations iterations simulations CPU hours measurements

190 745 30 17,100 2.3 million 123,205

Ebru Bozdag

Depth 75 km

Middle Hungarian line

Pannonian Basin

Massif Central

Central graben

Armorican Massif

Harz

Tornquist-Teisseyre Zone

Bohemian massif

Central Slovakian volcanic field

Eifel hotspot & Rhine graben

Alps slab

Cross sections

Eifel plume

Lithospheric delamination

Karin Sigloch *08

Seismic tomography: 3-D images of the mantle

Big challenge: the mantle in 4-D

Can the tomographic images be reconciled with plate reconstructions, land geology?

Waveform tomography using broadband data

Triplicated P waves from a mb 6.4 event, recorded by USArray. These are very strong signals (unlike receiver functions, underside reflections). They have rarely been used for tomography, since they require full waveform modelling.

S. S

tähl

er

Traveltime sensitivity kernels of P waves that are triplicated by the discontinuities of the mantle transition zone. Computations are done with the axisem code by Nissen-Meyer et al. 2007 (full 3D wavefields in a spherically layered earth, across the entire usable frequency range).

410 km

670 km

Waveform tomography using broadband data

Imaging a mantle plume under La Réunion

Imaging a mantle plume under La Réunion

Frederik Simons

Today’s geophysics is producing innovative

instrumentation

Bud Vincent

Text Text Text

Chris Harig

signal processing���

Kevin Lewis

Alain Plattner

Today’s geophysics is as engaging as it once was...

... but the undergraduates are just as tired as ever !

Richard Allen *01

Reaching Beyond the Ivory Tower: Reducing earthquake hazards ...while driving scientific discovery

As an example: Providing earthquake early warning …while learning about earthquake rupture

…and waveform propagation effects …and seismotectonics …and…

California’s earthquake problem

UCERF 2008 – USGS, CGS, SCEC

My office!

CISN California Integrated Seismic Network

Shake Alert

M3.5 Aromas Earthquake

…near the epicenter of

Loma Prieta

My desktop …on Friday

afternoon

ETH

Warning before an

earthquake

CISN California Integrated Seismic Network

Shake Alert

My desktop …on Friday

afternoon

ETH

M3.5 Aromas Earthquake

…near the epicenter of

Loma Prieta

Warning before an

earthquake

A public warning system…

Plans for:

• ~100 new seismic network stations

• Highrate realtime GPS stations

Dual use:

• Earthquake early warning

• All other research

…requires improved geophysical

networks

Dat

a: N

odal

Seis

mic

V

isua

lizat

ion:

Mag

ali B

arba

, Rob

Cla

yton

5km

7km

NodalSeismic Deployment

• Long Beach California

• 5000 geophones

• 6 months

…made data available!

river channel

highway

Dat

a: N

odal

Seis

mic

V

isua

lizat

ion:

Mag

ali B

arba

, Rob

Cla

yton

Smartphones? …the next generation of seismic network

California today: ~2000 seismic stations

~16 million smartphone accelerometers

…and around the world?

Smartphones • Accelerometers motion • GPS/wi-fi location • Magnetometer orientation • Built in communications

Big challenges…

the cloud

Realtime earthquake information

Waveform data for research

iShake Cal

Done.

Today’s geophysics is more than ever connected to

statistics

Sofia Olhede