Enhancement of Caltech’s crossborder collaborations in Geology
and Geophysics
Joann Stock, Robert Clayton
California Institute of Technology
SCEC – gateway, includes individual wiki pages for rapid earthquake response
Our current collaborators (Mexican
institutions)
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CICESE Ciencias de la Tierra
UNAM Instituto de Geofísica, México D.F.
UABC Ensenada
UABC Mexicali
Universidad de Sonora, Hermosillo, Sonora
California Integrated Seismic Network –
628 stations
Red: our network
Blue: external but contributed to our
network
CISN main data products
• Rapid locations of earthquakes
• ShakeMaps (observed & predicted ground shaking due to an
earthquake)
• Software for rapid distribution of earthquake information to
emergency management centers (ShakeCast)
• Strong motion records of engineering interest
• Seismological data for all recorded earthquakes for Southern
California, archived in the Southern California Earthquake Data
Center (SCEDC)
• Currently beta testing Earthquake Early Warning system
Example of ShakeMap product
• Transmission of seismic data in both directions across the border:
from seismometers in Mexico to data center in Mexico City and from
there to the Southern California Seismic Network Data Center; and
vice versa
Data
center
Data
center
SCEDC
Research and societal goals: better locations of earthquakes near the
US-Mexico border; duplicate archiving of data for regional
earthquakes; understanding geometry of sources of earthquakes in
Mexico and USA
Seismology collaborations, 1
Data volume: 2.6 Gigabytes of data transferred in both directions each
day
Takes anywhere from 1 to 3+ hours to transfer these data from Mexico
City to Pasadena
Data volume expected to increase to 5 Gbyte/day as network is
upgraded
Current network speeds
Seismology collaborations, 2
• Deployment of temporary web-enabled seismometers in
the Mexicali Valley, after the April 4, 2010 El MayorCucapah earthquake
Goal: better locations of earthquakes in the aftershock
sequence
Data volume: 4 Gbyte CF card stores data (2 – 4
weeks for typical recording parameters)
Instrument can be directly connected to the web via an
internet drop (no need for local computer)
Seismometer
& data logger
Challenge encountered: inability to connect to internet
Seismology collaborations, 3 (CICESE
and UABC-Mexicali)
Remember the question during Minster’s talk re: why did the earthquake
simulation stop at the border?
Active-source seismic imaging experiment in the Salton Trough (Mexicali-Imperial
Valleys) in 2011
• 126 explosion sources, about 4000 seismometer locations, recording rate 250-1000
Hz x 7 hours /day/deployed sensor
• 1 Terabyte total shot data from main experiment
Goals: improve knowledge of fault geometry, basin seismic velocity model for better
understanding of earthquake hazards;
Understand geological rifting processes
Current collaboration model: project Wiki (based on MindTouch) for planning
purposes, evolved to interchange data and keep record of all presentations & products
SSIP
SSIP
onshore seismic
refraction
& reflection
Wet-SSIP
marine seismic
refraction
& reflection
Broadband-SSIP
onshore
broadband
teleseismic
Hole SCEC 2011
SSIP
Feb. – March 2011
explosive shots
126 shots
median 115 kg
up to 1400 kg
SSIP+Wet-SSIP
Feb. – March 2011
seismometers:
3856 1-component
Texan sites
272 3-component
RT130 sites
78 3-component
OBS sites
Swath bathymetry data
The multibeam system is built into
the hull of the ship, or in a
separate towed unit. Transducers
in a cross-array pattern emit and
receive 12 kHz energy to image
the seafloor beneath the array
Multibeam echo sounder shows the shape of the seafloor below
N
Bathymetry of the mouth of the Gulf of California from Lonsdale et al.
Alarcon Rise is the southernmost Pacific-North America spreading segment
• Example data file
from East Pacific Rise
in southern Gulf of
California
• Colors show slope of
seafloor
• Data analyzed using
MB-system software
We would like to have joint real time work sessions to analyze these
data – but data files are large (compressed size 15-100 Mbytes/ hour
of survey, depending on water depth and type of system used)
Marine Geophysical Data
Wish List:
Fast, redundant connections between seismic data centers in both
countries
• MOOC – virtual geology field trips
• needs 3D capability;
• can accommodate larger groups of students than possible on
regular field trips
Participation by cross-border researchers on committees of
graduate students (MS, PhD) at CICESE, UniSON, UNAM
(D.F.). We need technology to have video conferencing routinely
available with ability to see & hear all participants, share data files
in real time
Expand capability & integration of mobile devices
Mexican Geophysical Union
webinar series
Once – per – month presentation over the internet on a science topic of interest to
the members of the Mexican Geophysical Union.
One hour talk + discussion; viewers register from any web enabled computer, and
receive link to connect and listen to and watch the presentation.
Talks can originate at various locations (UNAM, Mexican Petroleum Institute,
ERNO, etc). Powerpoint file with presentation can be downloaded later
Difficulties encountered with speed of transmission, loss of audio