Caltech Seismological Laboratory

Policymakers, community leaders, emergency managers, and engineers, save the date! hosts Northridge30 Symposium at Caltech, marking 30 years since the Northridge earthquake. Experts will share their experiences, discuss engineering progress, lessons learned, and more. Join us for this milestone event! https://seaosc.org/northridge30

Weekly Earthquake Stats: 31 Dec 2023 - 06 Jan 2024. There were 281 events this week ranging from M 0.19 to 4.15. Check out our weekly playback map and visit www.scsn.org for detailed information.
Caltech Seismological Laboratory

Welcoming 2024 with seismic insights from the SCSN in 2023! From the Ojai M5.1 to 22% fewer M

Happy Holidays from the Caltech Seismological Laboratory! We'll be back with more updates and content from the lab after the new year!

211 years ago, the 1812 Santa Barbara EQ razed the church at mission Santa Barbara. Did this event cause a tsunami? A news article from 52 years later claimed a ship was swept a mile up Refugio Canyon! No evidence exists to support this claim but it still offers an intriguing glimpse into CA's coastal past! And this was before we had observational networks so it was hard to even locate a possible M7, let alone finding out if a tsunami occurred!

1812 Santa Barbara Earthquake: Tsunami! "At the time [of the 1812 earthquakes] a Boston ship, the Thomas Newland, known before as the Charon, commanded by Capt. Isaac Whittemore, was lying off anchorage [at Refugio Bay], not far from the Gaviota Pass, Santa Barbara County, engaged in smuggling, with the old Padres, for otter skins, tallow...

Check out some highlights out of the Seismo Lab in Caltech's 2023 Year in Review! From revolutionary seismic discoveries and applications using fiber-optic cables to lunar quakes and cosmic origins, our community has been busy!

2023 Year in Review As the end of 2023 draws near, Caltech News looks back at our coverage of the research, discoveries, events, and experiences that shaped the Institute. Here are some highlights.

Meet Anna Gülcher, a Seismo Lab Post-Doc who specializes in using geodynamic modeling tools to advance our understanding of mantle convection, tectonics, and magmatism on rocky planets like Earth and Venus! Anna Gülcher NASA Jet Propulsion Laboratory www.annagulcher.com

Last week Ariel Raymond, Earthquake Fellows Program Coordinator, was thrilled to have showcased the Earthquake Fellows Program at during the "Efforts to Support and Increase Diversity in the Earth and Space Science Workforce" session. Empowering students from diverse backgrounds to explore geoscience is a step towards a more inclusive future in Earth and space sciences! Learn more at: https://seismolab.caltech.edu/eq_fellows.html

Weekly Earthquake Stats: 10 Dec 2023 - 16 Dec 2023. There were 253 events this week ranging from M-0.06 to 2.99. Check out our live weekly playback map and visit www.scsn.org for detailed information.

Today at 4pm, Yan Yang will be presenting "Refining Firn Density Estimations at the South Pole using Distributed Acoustic Sensing" where they discuss South Pole fiber-optic sensing: they captured 16+ dispersion modes to refine seismic velocity model, improving firn density estimates at East Antarctica.

Today at 2:10pm, Gabrielle Tepp will be presenting "Bringing Machine Learning into Event Post-processing at the Southern California Seismic Network" where they discuss how they implemented a deep-learning algorithm in seismic event post-processing for monitoring that produces better automatic locations and phase picks.

Bringing Machine Learning into Event Post-processing at the Southern California Seismic Network During regular seismic network operations, data is automatically analyzed in re...

Victor Vescu will be presenting "The Effect of Thermal Stresses on Injection-Induced Seismicity" where they numerically simulate thermal changes in subsurface stress and accompanying seismicity rate changes caused by underground injection of cold fluids. Victor Vescu

The Effect of Thermal Stresses on Injection-Induced Seismicity A better understanding of the mechanisms driving injection-induced seismicity r...

Today at 12:00pm, Tobias Köhne will be presenting "Historically Consistent and Geodetically Constrained Bayesian Inference of Megathrust Rheology" where they discuss building a subduction zone model based on historical earthquakes to match it with geodetic observations to estimate rheological properties. https://agu.confex.com/agu/fm23/meetingapp.cgi/Paper/1424599

Version 2.0 of timeseries analysis package DISSTANS now available: https://github.com/tobiscode/disstans/

Today at 11:20am, Dr. Anna Gülcher will be presenting "Prolonged tectono-magmatic lifetimes and eclogite recycling at asymmetric coronae on Venus" where they present a joint study of mission data analysis and 3D numerical modeling on asymmetrical coronae on Venus , , , https://agu.confex.com/agu/fm23/meetingapp.cgi/Paper/1318297

Today at 9:30am, Qian Yuan will be presenting "A Giant Impact Origin for the First Subduction on Earth" where they discuss how the thermochemical structure of the mantle created by the Moon-forming giant impact creates a mechanism for the earliest subduction initiation. My tweet ID is NA

Today at 8:30am, Qiushi Zhai will be presenting "Instrument Performance Evaluation and Seismic Signal Classification of a DAS Array at the South Pole" where they discuss how they deployed a DAS at the South Pole! The initial two weeks' data shows great instrument performance, capturing seismic signals from diverse sources.

Instrument Performance Evaluation and Seismic Signal Classification of a DAS Array at the South Pole Polar and glacial seismology can help better understand the lithosphere and cry...

Today at 2:10pm, Hojjat Kaveh will be presenting "Predictability of extreme events in a dynamical model of earthquake sequences" where they explain how they spatiotemporally forecast large events in a synthetic catalog of chaotic sequences of events using the fault self-organization into a chaotic set. https://agu.confex.com/agu/fm23/meetingapp.cgi/Paper/1284318

Later today at 5:15pm, Ben Strozewski will be presenting "Seismic wave speeds of (Al,Fe)-phase H and the detectability of dense oxyhydroxides in Earth’s lower mantle." This research constrains sound velocities of (Al,Fe)-phase H, a dense oyxhydroxide, to better understand hydrogen transport in Earth's deep interior. Read more at: http://bstroze.github.io https://agu.confex.com/agu/fm23/meetingapp.cgi/Session/209046

started yesterday and so far we've had a great showing! Check here over the next few days as we highlight some of the Caltech Seismo Lab participants and their exciting new research and discoveries!

Weekly Earthquake Stats: 03 Dec 2023 - 09 Dec 2023. There were 289 events this week ranging from M0.25 to 3.65. Check out our live weekly playback map and visit www.scsn.org for detailed information.

Wrapping up another great year with a ton of appreciation! Our team gathered for an end-of-year luncheon, celebrating teamwork, dedication, and a faultless commitment to keeping SoCal informed. Here's to more seismic success in the new year!

Meet Mark Simons, a Seismo Lab Professor, with the lab for 27 years! Mark specializes in crustal deformation of different flavors, geodynamics, glaciology, and planetary geophysics, all with an emphasis on uses of space geodesy!
https://web.gps.caltech.edu/~simons/

Weekly Earthquake Stats: 26 Nov 2023 - 02 Dec 2023. There were 283 events this week ranging from M-0.01 to 4.77. Check out our live weekly playback map and visit www.scsn.org for detailed information.

Happy Thanksgiving from all of us at the Caltech Seismological Laboratory! Grateful for the seismic shifts in knowledge, the strength of our scientific community, and the stability of our research. Wishing everyone a day filled with warmth, joy, and calm seismicity!

On this day in 1800 a ~M6 EQ in the San Diego area occurred. Contemporary accounts exist only in San Diego and Capistrano mission records, making location poorly constrained. Catalogs have it offshore, but field studies have also supported its location along the Clark fault.
https://earthquake.usgs.gov/earthquakes/eventpage/ushis19/executive
https://pubs.usgs.gov/publicatio/70157149

Weekly Earthquake Stats: 12 Nov 2023 - 18 Nov 2023. There were 178 events this week ranging from M0.11 to 3.35. Check out our live weekly playback map and more by visiting www.scsn.org. Caltech Seismological Laboratory

DAS arrays offer incredible insights, providing strain measurements across extensive telecom cables, a boon for earthquake monitoring. But, storing this data poses significant technical hurdles. A single 100km long DAS array consists of 10,000-components and generates 80 TB annually at 100 Hz sampling! By comparison the SCEDC's total seismic waveform archive from 1977-2023 is about 100 TB!

Live DAS Stream | SCSN Below is a real-time feed of data from a distributed acoustic sensing (DAS) array located in Southern California. DAS data is obtained by attaching instruments to existing fiber optic cables owned and installed by various telecommunication companies throughout California. The feed below displays the...

Weekly Earthquake Stats: 05 Nov 2023 - 11 Nov 2023. There were 198 events this week ranging from M0.04 to 3.87. Check out our live weekly playback map and visit www.scsn.org for detailed information.

If you are looking for earthquakes in our Live DAS Feed, it would probably help to know what you are looking for! Due to the velocity the EQ waves travel through the ground, at this 30-minute time scale they appear as a horizontal line! Scroll back through the display and see if you can spot any! If you post screenshots in the chat we will confirm if they are earthquakes this Sunday 11/12!
Visit our Understanding DAS Data page for more info:
https://www.scsn.org/index.php/education-outreach-2/understanding-das-data/index.html

Also note, the pictured EQ is a very close M3.5 which registers on the array very prominently. Smaller or distant EQs can show up thinner and less vibrant, so keep an eye out for those flat lines! And check our Live Seismograms feed on www.scsn.org to see if it is visible there!

Big News! The SCSN is taking seismic monitoring and research to the next level with Distributed Acoustic Sensing (DAS)! We're now live-streaming seismic data from an 80km long DAS array in Ridgecrest, CA! View the stream and learn more at:

https://www.scsn.org/index.php/earthquakes/live-das-stream/index.html

And for you earthquake watchers out there, the direct feed is also now available on the SCSN youtube channel! Make sure you take a look at the event examples and What am I seeing page on www.scsn.org so you know what to look out for!
https://www.youtube.com/live/LOeIHhbFxys?si=Bhc6NcCmR_IL_csi

SCSN Live Distributed Acoustic Sensing (DAS) Feed Want to know what you are looking at? Go to https://www.scsn.org/index.php/earthquakes/live-das-stream/index.html for more information. This is a real-time f...