From the Director: Summertime, and the Livin' is Busy


Learning from a Disastrous Megathrust Earthquake

What causes earthquake foreshocks?

Study reveals the workings of nature’s own earthquake blocker

NASA Balloon Detects California Earthquake – Next Stop, Venus?

UNAVCO and IRIS Joining Forces for Advancing Geophysics

Lucy Jones says this is the most important thing you can do to prepare for a quake

Surprising recharacterization of earthquake risk along a strand of the San Andreas

Tim Ahern, Director of Data Services-Emeritus, Receives SSA’s 2021 Frank Press Public Service Award

In major milestone, U.S. earthquake early warning system now covers entire West Coast

When it comes to earthquakes, size matters but so does the terrain

Read the Spring 2021 Issue of the IRIS Data Services Newsletter

Who is most vulnerable during a major Northern California earthquake?

More news...

Dear SCEC Community,

June 28 marks the 29th anniversary of the 1992 M7.3 Landers earthquake in the Eastern California Shear Zone (ECSZ), which was preceded by the M6.1 Joshua Tree event on April 23 and was followed about 3 hours later by the M6.5 Big Bear earthquake. The ECSZ subsequently hosted the October 1999 M7.1 Hector Mine and the July 2019 M7.1 Ridgecrest earthquakes. These major events and their aftershock sequences provided detailed modern data on many fundamental aspects of earthquakes, including long-range dynamic triggering of seismicity and the complex multi-segment character of large events, to name a few. These and other features motivated the development of new broader perspectives on the physics of earthquakes and faults that extend classical views.

Coseismic near-field and off-fault surface deformation patterns of the 1992 Landers and 1999 Hector Mine earthquakes. From Milliner et al. (GRL, 2016).

The set of major earthquakes that started with the 1992 Landers event also highlighted collectively the important role the linear zone extending from the southern San Andreas fault through the ECSZ to the Walker-Lane has on the current tectonic activity in southern California. Several studies suggested that the main plate-boundary in southern California is in the process of migrating from the big-band section of the San Andreas fault to this active linear zone in eastern southern California. We will continue to pay close attention to this highly active zone of deformation, and will continue efforts to extract new information from the generated data. In particular, the seismic, geodetic, topographic and geologic datasets gathered during the rapid scientific response to the 2019 Ridgecrest earthquake sequence have high potential for leading to additional new discoveries. 

A cornerstone of the SCEC collaboration is the self-organization of researchers into technical activity groups (TAGs) to develop and test critical methods to solve specific problems. A new SCEC/USGS Technical Activity Group (TAG) has formed to focus community efforts on resolving discrepancies in derivations of earthquake stress drops. Led by Annemarie Baltay and Rachel Abercrombie, the group has launched a validation study using the 2019 Ridgecrest aftershock sequence data. To learn more about the group and how to participate in the study, see their article in this issue. Through these TAG activities, the SCEC community has been able to tackle problems that individual investigators have grappled with and accelerated research in different fields.

The embodiment of these coordinated efforts is the SCEC community models, which transform voluminous and complex datasets of earth’s structure in ways that make it useful for research by the broader community. Many SCEC participants are involved in creating, synthesizing, refining, and disseminating these valuable datasets and models. The latest and most comprehensive version of the SCEC Community Fault Model (CFM5.3) was recently released, with improved tools for accessing the CFM through a web interface. We expect to hear more about new versions of other community models and products later this year, following peer evaluations.

Last winter, SCEC partnered with IRIS and UNAVCO to develop a Rupture and Fault Zone Observatory (RuFZO) that will allow the recording of critical data within and around earthquake rupture zones. The RuFZO design focuses on the immediate vicinity of large fault zones, where rocks suffer permanent deformation during faulting events, and it aims to capture on-scale ground motion within 0.1 km to 3 km of major faults before, during and after ruptures. Such data are needed for testing and developing further models of earthquake processes. Measurements by the near-fault RuFZO sensors during interseismic periods would provide unprecedented characterization of structures, which can improve derivation of earthquake properties, interpretation of geodetic data and simulations of ground motion. 

In March we submitted a pre-proposal to the NSF Mid-Scale RI-2 program and in April we conducted a Community Workshop to get feedback on how the RuFZO facility may best serve the community. The half-day event with over 300 participants had lively discussions and exchanges, which provided important feedback on the goals, design, and locations of the RuFZO arrays. In mid-June we were informed by NSF that the RuFZO project was not invited to the next round of this year’s competition. We plan to pursue the RuFZO concept at a later opportunity, and will use the time until the next competition to refine the experimental plan and design of the RuFZO arrays. 

SCEC, IRIS, and UNAVCO have also explored other ways to leverage our complementary strengths in research on fundamental and applied problems of earthquake science, geophysical instrumentation, data handling, workforce training, and outreach and education. The three organizations have recently signed a formal MOU to foster cooperation, coordination, and partnership in support of broad research objectives in earthquake science, earth structures and mechanics, and natural hazards. Useful joint efforts include rapid scientific response to major earthquakes, benchmarking and validation of novel sensors and methods, enhancement of scientific software and cyberinfrastructure capabilities, and development of educational resources to engage broad audiences on geologic hazards.

During the week of June 6, a large multi-disciplinary team co-led by SCEC hosted the Societal Shock Resilience Workshop as part of the idea-creation step in the NSF Convergence Accelerator program. This NSF program was created to focus convergence research and innovative approaches to address national-scale, high-impact societal challenges. Over 200 participants from across the globe represented a wide range of disciplines and diverse experiences. The topics discussed include shock and hazard quantification, mitigation, recovery, communication and education, public policy, equity and justice, and model integration to name a few. The organizing team is now synthesizing the workshop outcomes into recommendations for NSF on a potential funding track for convergence research on societal shock resilience. We expect continuing discussions and seed activities that will foster collaborations among various groups working on natural hazards.

The Center’s Communication, Education, and Outreach program continues to promote community resilience in many ways. With funding from FEMA/NEHRP, SCEC coordinates ShakeOut Drills nationally. On April 15, more than 730,000 people participated in the Utah ShakeOut. International ShakeOut Day is on October 21 this year, and the CEO group is developing new features for the ShakeOut website ahead of the drill. SCEC’s website (funded by NOAA/NWS through Cal OES) supports tsunami preparedness activities for 184,000 Californians and nearly 350,000 people throughout the Caribbean (“Caribe Wave”), and now includes information for Alaska, Guam, Hawaii, Oregon, and Washington. This spring, the SCEC-led Earthquake Country Alliance (also funded by Cal OES, with FEMA/NEHRP state support) held online workshops for Southern California (on equity, diversity, and inclusion within earthquake mitigation) and the Bay Area (on lessons from New Zealand earthquakes), and the first Community Engagement Webinar featuring local programs from across California. Join the ECA to receive updates on upcoming workshops, training, and webinars and other ECA and ShakeOut resources, many of which will be translated into 14 languages this summer.

Summertime is often the start of travel, fieldwork, and other research activities for our SCEC scientists, and research and internship opportunities for our students. The Supported Opportunities for Undergraduates and Researchers to Collaborate on Earthquake Science (SOURCES) internship program, which is managed by CEO’s Office of Experiential Learning and Career Advancement (ELCA), recruited 15 interns and 11 mentors for the summer session to work on a variety of projects together. Expanding on the success from 2020 (when SOURCES was launched), the program will provide research opportunities to undergrads nationwide during the summer and into the 2021-2022 academic year. You can read about how SCEC mentors supported and trained—and benefitted from working with—our next generation of researchers in the article on lessons learned from the 2020 cohort of mentors. The next Research Mentor Training Workshop will be held on July 7-8 and will focus on developing skills for engaging in productive, culturally responsive, research mentoring relationships. Capacity is limited so register soon to participate.

On May 24-25, the SCEC leadership gathered online again for an “annual retreat” to evaluate the state of SCEC and to plan for the next phase of the Center. We focused on refining the scope of research targets and other activities for the bridge period (or 1-2 years until the next earthquake center competition). We are currently working with SCEC core institutions and agency program managers to ensure smooth operations during this term. In planning for the future, the SCEC leadership concluded that the bridge period offers important opportunities to update operations that would improve our ability to conduct state-of-the-art research and education activities, and be better positioned for the next Center. One general area of growth could be for research computing to have a more foundational role in advancing Center-wide activities. The task force on research computing (chaired by Artie Rodgers) that was formed in February provided in the leadership meeting important recommendations on how to improve software development, data management, training, project coordination, and other collaborative research practices to better serve the SCEC community and our partners.

The Center has already begun adapting practices towards these improvements. In this issue, three articles highlight how SCEC software enables research on ground motion simulation and validation (SCEC BBP), earthquake forecast evaluations (pyCSEP), and community model development (CFM viewer). These scientific software and access tools, along with our team’s ability to successfully compete for HPC allocations on national leadership class supercomputers, are essential for achieving SCEC research goals. Each year, a team of researchers led by Christine Goulet plans advanced simulations and develops proposals for HPC resources from the NSF Extreme Science and Engineering Discovery Environment (XSEDE), Large-Scale Community Partnerships (LSCP), and DOE Innovative and Novel Computational Impact on Theory and Experiment (INCITE). This month, we received two new awards for run time on Stampede2 and Bridges Extreme Memory Nodes through XSEDE, and on Frontera through LSCP. We expect to hear about the INCITE proposal later this year.

We look forward to learning about many achievements from the SCEC community in September at our annual meeting. The re-opening of California continues as we emerge from pandemic conditions. However, some uncertainty for the fall remains, so we are preparing for a fully-online 2021 SCEC annual meeting. We have begun to develop the online meeting platform, building on the successes from SCEC2020. The SCEC Science Planning Committee is working to finalize this year’s program. Everyone is invited to submit poster abstracts to share research and educational results with the community, and the meeting will include as usual a set of exciting oral presentations. The annual meeting registration will open in July.

In closing, I would like to express my strong appreciation of Co-Director Greg Beroza for his many fundamental contributions to SCEC and earthquake science over the years, and to congratulate him for receiving the Humboldt research prize this year. This newsletter includes an interview with Greg about this honor and other topics. Cheers to Greg!

Best wishes and regards,

Yehuda Ben-Zion, SCEC Director

Science Highlights

New SCEC/USGS Community Stress Drop Validation Study Launched

A new SCEC/USGS Technical Activity Group (TAG) has been formed to focus community efforts on resolving discrepancies in earthquake stress drop, beginning with a validation study of the waveform recordings from the 2019 Ridgecrest earthquake sequence. We invite anyone interested to join this community validation study and the new Stress Drop TAG research efforts. By determining whether the stress drop varies with tectonic setting, orientation, earthquake magnitude or any other observable parameter, we can improve ground motion prediction and provide constraints on the factors controlling earthquake rupture. [read full article]

SCEC Community Fault Model v5.3 Released with Updated Web Tools for Improved Access

We are pleased to announce the release of version 5.3 of the SCEC Community Fault Model (CFM5.3) — the most detailed and comprehensive 3D representation of southern California faults to date. CFM5.3 contains 440 individual fault representations in the preferred model and includes many alternative representations, as well as numerous new and updated fault models and detailed 3D representations of the faults responsible for the 2019 M6.4 and M7.1 Ridgecrest earthquakes. This latest version adds new features that make CFM even more accessible to the earthquake community. [read full article]

SCEC Broadband Platform for Ground Motion Simulation and Validation

The SCEC Broadband Platform (BBP) is a collection of open-source codes used to simulate broadband (0-20+ Hz) ground motions for historical and scenario earthquakes. A team of SCEC researchers including scientists, engineers, and computer scientists develop, verify, and validate the scientific models and analysis codes in the platform and then release them as open-source software. The latest Broadband Platform release, version 19.8.0, is available for download on GitHub. The SCEC BBP is designed to be used by both geophysicists and engineering researchers with some experience interpreting ground motion simulations. [read full article]

Sustainable Research Software through Open-Source Communities

The Collaboratory for the Study of Earthquake Predictability (CSEP) developed a Python toolkit (dubbed pyCSEP) for evaluating and working with earthquake forecasts. It was developed from the ground up to encourage researchers to contribute code directly to the toolkit—while their research is in progress. Contributed code is then immediately available for others to use, test, or further refine. It’s hard to argue the benefits of this approach: shared analysis routines, confidence that results can be replicated across research efforts, and citable toolkits. Developing toolkits of functions designed to work together in streamlined workflows addresses some fundamental issues facing software sustainability in the earth sciences. [read full article]


Education Highlights

5 Powerful Lessons From SCEC’s Exceptional Research Mentors

As the 2021 internship season gets underway, we can tap into powerful lessons learned from the 2020 program. Despite their own personal and professional challenges, mentors of the SCEC SOURCES internship program consistently supported undergraduate student researchers, most choosing to extend their mentoring throughout the entire 2020-2021 academic year. Some mentors reshaped projects to fit a remote mentoring model, while others invested in equipment so interns could work at home. SCEC mentors demonstrated our community’s commitment to supporting and training our next generation of researchers when they needed it most. [read full article]


Researcher Spotlight

SCEC Co-Director Greg Beroza Receives Humboldt Research Award

Greg Beroza, Wayne Loel Professor of Geophysics at Stanford, and Co-Director of SCEC, has been awarded the prestigious Humboldt Research Award (also known as the Humboldt Prize). The award is granted each year by the Alexander von Humboldt Foundation to recognize up to 100 researchers of all disciplines from around the world, whose discoveries or insights have had a lasting impact. For Greg, this recognition is based on his research and teaching excellence. In addition, his multiple leadership roles within SCEC have provided Greg a unique perspective on the evolution of the SCEC Collaboratory and the overall study of earthquakes which informs his vision for the future. He shares his views in response to a few questions. [read full article]