Home  /  Workshops  /  SCEC-IRIS-UNAVCO Community Workshop: Rupture and Fault Zone Observatory (RuFZO)

SCEC-IRIS-UNAVCO Community Workshop: Rupture and Fault Zone Observatory (RuFZO)

Conveners: Yehuda Ben-Zion, Robert Busby, Rebecca Bendick, Frank Vernon, Tran Huynh, and Kasey Aderhold
Date: April 13, 2021 (08:00-12:00 PDT or UTC-7)

See full workshop playlist on YouTube

HOW TO PROVIDE INPUT: Throughout spring and summer 2021, you are invited to provide input and feedback on RuFZO by multiple means:

Complete this online questionnaire. Your input and feedback will be shared with the RuFZO project leadership and help to inform proposal development.

Contribute a lightning presentation. Record your ideas for the RuFZO as a video presentation (up to 5 minutes max). We will make available videos and abstracts for which authors have granted permission to share publicly. See playlist linked above.

Contribute an extended abstract with figure. You may also provide input by submitting an abstract (2500 characters max) and figure online. These will also be shared at the workshop only or publicly, with the authors’ permission

BACKGROUND: Geophysical data within rupture zones of significant earthquakes are essential for testing and developing further models of earthquake processes. However, such data have never been captured in-situ because this undertaking requires continuous measurements with dense array sensors concentrated near faults. Recently, a joint SCEC-IRIS-UNAVCO collaboration responded to NSF’s Mid-scale Research Infrastructure-2 solicitation by proposing a systematic deployment of linear instrumental arrays that cross the three major branches of the San Andreas system in southern California. The proposed Rupture and Fault Zone Observatory (RuFZO) is focused on in-situ observations in the immediate vicinity of fault zones where rocks suffer permanent deformation during faulting events. Near-fault arrays collecting continuous seismic and geodetic measurements and dense temporary nodal surveys will complement, and be integrated with, the data recorded by the regional networks. The novel data captured by RuFZO could transform the understanding of earthquake physics, improve ground motion prediction estimates, and contribute to structural engineering efforts to mitigate earthquake impacts – important priorities identified in the NAS CORES (2020) report.

Our aim is to gather input from the broader earthquake science community about how the RuFZO can better serve the community. That is, what are key research areas and data needed to address them, or experiments to incorporate into the RuFZO science plan and facility design, along with opportunities to complement research done by early warning and regional sensors. The community’s input will inform the development of the full proposal.

WORKSHOP SUMMARY: The Rupture and Fault Zone Observatory Workshop held on April 13th, 2021 engaged 325 people for presentations, discussions, and feedback on the plans for this proposed facility. The half-day event was held as a Zoom meeting including video and text chat, augmented with survey questions and targeted input requests  before and after the formal meeting. 

The workshop discussion was wide-ranging and lively, and it is difficult to distill the considerable feedback received from the participants into a short summary. In the following, we summarize some main topics, especially issues that have potentially large influence on the design, schedule or budget of the project. Identifying a few key science questions is critical to developing design elements such as instrumentation types, sensor network geometry, and data specifications and flow.

08:00 - 09:00    Overview of RuFZO: Science Motivation, Facility Design, and Training
Moderators: Tran Huynh and Rebecca Bendick

Presentations and discussion in this session covered the proposed scientific target: seismic and geodetic measurements from within or very near rupture zones, before, during and after earthquake ruptures. These measurements will enable novel insights into the fundamental physics of faulting and the associated hazard.  The RuFZO leadership team presented an initial design concept with locations of focus arrays, extent of the RuFZO geographical region, and array station layouts.

09:00 - 10:00    Seismic Observations and Key Science Questions
Moderators: Frank Vernon and Jamie Steidl

This session covered a range of seismic science applications. This prompted discussion of optimal seismic observations, complementary observations, array locations, and alternative geographic regions where RuFZO might be effective (e.g. Carrizo Plain, Hayward Fault), and how all of these factors will impact the science questions that can be answered by this facility.

10:00 - 11:00    Geodetic Observations and Key Science Questions
Moderators: Andrea Donnellan and Jean-Philippe Avouac

This session covered geodetic science observations and was followed by discussion of resolution and uncertainty of geodetic techniques, characterization of focus array sites and network geometry, and the role of fluids in fault behavior.

11:00 - 11:55    How can the RuFZO best serve the earthquake science community?
Moderators: Bob Woodward and Adrian Borsa

This session stimulated a wide-ranging discussion of scientific targets and the methods required to address them. The moderator team compiled overview questions based on the previous sessions and resulting discussions; these questions will inform the next iteration of experimental design.

  • Session 1: RuFZO Science Motivation, Facility Design, and Training
    • What is the optimal physical layout (spacing and length) of fault-crossing sensor arrays  (imaging depth vs resolution) and what is the influence of logistical/budget constraints?
    • Is there a need for 2D aspects to augment 1D Nodal Surveys?  Is there a need for additional off-fault seismic/geodetic instrumentation?  How far?
    • What other instruments/observations would best complement the RuFZO backbone? 
    • How should we incorporate the needs of other communities and/or non-expert stakeholders into the facility design and operation? Particularly, how to accommodate add-on experiments that leverage the ‘facility? Engineering community needs?
    • Given that space geodetic techniques are key to constraining co/post/interseismic deformation, how might RuFZO improve integration of ground-based sensors with satellite observations--e.g. adding reflectors or campaign benchmarks?
    • Do the chat comments adequately highlight the range of science that can be done even absent a single large rupture?
  • Session 2: Seismic Observations and Key Science Questions
    • What is the primary target of the facility: identifying sources or characterizing fault and surrounding region? How does this inform the frequencies that should be prioritized by RuFZO?
    • How might RuFZO consider hydrology/fluids in the context of seismicity and seismic propagation?
    • Is there a place for active-source seismic experiments during the RuFZO nodal deployments?
    • How does RuFZO differ from and expand on earlier/existing experiments and networks (e.g. Parkfield, SJF nodal array)?
    • How does RuFZO nest within and leverage other sensor networks?  What synergies can we highlight in  proposal development and in building partnerships?
  • Session 3: Geodetic Observations and Key Science Questions
    • How should we think about array aperture?  Should it be the same for the seismic and geodetic instruments?
    • What are the best approaches to adjoint combinations of geodetic and seismic observations?  Can we use edge computing and adaptive data handling to optimize on signal vs. bandwidth tradeoffs?
    • Role of the water table and fault zone fluids is critical for understanding seismic rupture and/or initiation. What are the critical observations needed for RuFZO?
    • Are there potential synergies around integrating dense RuFZO geodetic (and/or seismic) arrays with ShakeAlert and other EEW efforts?
    • How do we best approach understanding the tradeoffs of number of sensors, resolution, robustness, and other variables? Is the approach framed earlier (session #1) adequate to the science objectives?
  • Other Considerations
    • Are there specific needs or innovations in data management/archiving/delivery that should be emphasized for RuFZO?
    • How can RuFZO enable connections between the observations it will make and the big data modeling/analysis needed for interpretation?  
    • What are the two or three most critical science questions that could be answered with near-fault observations?

RECOMMENDATIONS: It is important to engage the community in forming a facility of this scale.  As exemplified here, there is no shortage of interest and constructive suggestions, which are hard to fully catalog. The challenge is digesting, synthesizing and incorporating ideas so as to increasingly refine facility attributes that are achievable and based on consensus. An approach will be to utilize the full day workshops to share plans and canvass for ideas, interspersed with smaller breakout groups to develop a topic, and then return to larger meetings for plan updates and out briefs.

We identify the topics below to refine in smaller virtual workgroups (numbering 4-7) and bring forward outbriefs of those to a future, full day workshop. These topics (except for the last) came up in several different forums, and further discussions among those keenly interested can improve the plan and potentially lead to consensus views.

  • Science goals to be addressed by instrumentation, data and modeling
  • Fault crossing array layout (spacing and length)
  • Training initiatives 
  • Nodal Survey layout options
  • Geodetic layout options, sample rates, EEW integration
  • Site characterization goals and options; prescreening discrimination or post siting assessment?
  • Suggested specific locations for focus areas

Some complementary observations, either through temporary surveys or with collocated instrumentation, were proposed. These will need to be prioritized based on scientific motivation and feasibility, that includes the cost of the sensors, installation, and/or permitting.

The location of sites, array geometry, and overall RuFZO layout will need to be considered, as identified above in specific contexts, but also in total thereby framing the overall scope, budget and schedule of the project.

WORKSHOP PARTICIPANTS: Anyone interested in the RuFZO project was invited to participate in the community workshops. Early career researchers and students were especially encouraged to participate and be involved. The proposed RuFZO is intended to help train future STEM workers, particularly in the design and implementation of large Geoscience facilities and in associated data analyses. The RuFZO facility will serve the earthquake science community by providing in-situ observations in the immediate vicinity of fault zones; and engage students and early career professionals through workshops, short courses, field trips, undergraduate internships, and graduate student awards.

Rachel Abercrombie (Boston)
Niloufar Abolfathian (JPL)
Digdem Acarel (Gebze Tech U)
Kasey Aderhold (IRIS)
Duncan Agnew (SIO/UCSD)
Richard Allen (UC Berkeley)
Abdulsalam Alzahrani (Kacst)
Jean-Paul Ampuero (GEOAZUR - IRD)
Kent Anderson (IRIS)
Muhajir Anshori (BMKG)
Daisuke Asahina (GS of Japan)
Richard Aster (Colorado State)
Luciana Astiz (NSF)
Ken Austin (UNAVCO)
Jean-Philippe Avouac (Caltech)
Annemarie Baltay (USGS)
Yohai Bar-sinai (Tel Aviv)
Monica Barbery (TAMU)
Sylvain Barbot (USC)
Serif Baris (Kocaeli U, Turkey)
Léo Barrois (Ens Paris Saclay)
Noel Bartlow (Kansas)
Andre Basset (UNAVCO)
Laura Bedoyan (Caltech)
Tena Belinić Topić (U Zagreb)
Yehuda Ben-Zion (SCEC/USC)
Mark Benthien (SCEC/USC)
Rebecca Bendick (UNAVCO)
Rick Bennett (U Arizona)
Rick Benson (IRIS)
Alexander Berne (Caltech)
Greg Beroza (Stanford)
Ali Biglari (GU)
Susan Bilek (New Mexico Tech)
Roger Bilham (U Colorado)
Michael Blanpied (USGS)
Yehuda Bock (SIO/UCSD)
Adrian Borsa (SIO/UCSD)
Maren Böse (ETH Zurich)
Florent Brenguier (Grenoble)
Emily Brodsky (UCSC)
Benjamin Brooks (USGS)
Matthew Burgess (San Diego County)
Roland Burgmann (UC Berkeley)
Robert Busby (IRIS)
Musavver Didem Cambaz (Boğaziçi)
Jerry Carter (IRIS)
Rufus Catchings (USGS)
Julianna Cativo (UCLA)
Kristel Chanard (IPGP )
Donna Charlevoix (UNAVCO)
Thomas Chen (AMSE)
Wang-Ping Chen (UIUC)
Yifang Cheng (USC)
Shanna Chu (Brown)
Rob Clayton (Caltech)
Elizabeth Cochran (USGS)
Steve Cole (OptaSense)
Lili Czirok (U Pécs)
Elisabetta D'Anastasio (GNS Science)
Tim Dawson (CGS)
Kimberly DeGrandpre (Michigan State)
Stratos Delogkos (U College Dublin)
Rita Di Giovambattista (INGV)
Xiaotian Ding (SUSTech)
Andrea Donnellan (JPL)
Matthew Dorsey (TAMU)
Benchun Duan (TAMU)
Cynthia Ebinger (Tulane)
Ahmed Elbanna (UIUC)
Linus Ayangwoh Embe (ASCOA)
Douglas Ertz (UNAVCO)
Chuck Estabrook (GWU)
Jim Evans (Utah State)
Wenyuan Fan (SIO/UCSD)
Noha Farghal (USGS)
Laura Fattaruso (UMass Amherst)
Karl Feaux (UNAVCO)
Eric Fielding (JPL)
Megan Flanagan (EditSprings)
James Flournoy (Save Our Community)
Michael Floyd (MIT)
Andy Frassetto (IRIS)
Yuning Fu (Bowling Green)
Gareth Funning (UCR)
Alice Gabriel (LMU)
James Gaherty (NAU)
Athanassios Ganas (National Obs of Athens)
Elyse Gaudreau (Victoria)
Ani Gevorgyan (Armenian Reg Survey)
Farid Ghahari (UCLA)
Doug Given (USGS)
Dara Goldberg (USGS)
Mariana Gomes (Rio de Janeiro)
Jose Gomez (Cal Poly Pomona)
Jianhua Gong (UCSD)
Jose Javier Gonzalez-Garcia (CICESE)
Christine Goulet (SCEC/USC)
Indra Gunawan (BMKG)
Hao Guo (Wisconsin)
Michael Gurnis (Caltech)
Katrin Hafner (IRIS)
Bill Hammond (UNR)
Catherine Hanagan (U Arizona)
Steve Harlan (NSF)
Ruth Harris (USGS)
Behzad Hassani (BC Hydro)
Alexandra Hatem (USGS)
Egill Hauksson (Caltech)
Jorge Nicolas Hayek Valencia (LMU)
Thomas Herring (MIT)
Stephen Hicks (Imperial College)
Gregor Hillers (U Helsinki)
Barry Hirshorn (Unaffiliated)
Kathleen Hodgkinson (UNAVCO)
Hinako Hosono (Nihon U)
Heidi Houston (USC)
Yu-Fang Hsu (Academia Sinica)
Hsin-Hua Huang (Academia Sinica)
Shuye Huang (USC)
Yihe Huang (Michigan)
Ruei-Jiun Hung (SDSU)
Allen Husker (Caltech)
Tran Huynh (USC/SCEC)
Lorraine Hwang (CIG)
Socrates Ibarra (MTWC)
Nadine Igonin (U Calgary)
Asaf Inbal (Tel Aviv)
Md Ariful Islam (U Dhaka)
David Jackson (UCLA)
Muhammad Tahir Javed (Trieste)
Chen Ji (UCSB)
Junle Jiang (Oklahoma)
Yu Jiang (Liverpool)
Christopher Johnson (LANL)
Scott Johnson (UNAVCO)
Wade Johnson (UNAVCO)
Frank Jordan (San Bernardino County)
Martin Karrenbach (OptaSense)
Aitaro Kato (ERI, Tokyo)
Chun-Yu Ke (Cornell)
Mostafa Khoshmanesh (Caltech)
Debi Kilb (SIO/UCSD)
Jey Kim (Stony Brook)
Saeko Kita (BRI)
Christina Kitamikado (UCLA)
Elliot Klein (FM Global)
Megan Kortink (GNS Science)
Kayla Kroll (LLNL)
Neha Kumari (IIT Roorkee)
Ogie Kuraica (Kinemetrics)
Grzegorz Kwiateck (GFZ Potsdam)
Christodoulos Kyriakopoulos (Memphis/CERI)
Lisa LaFlame (OptaSense)
Valere Lambert (Caltech)
Charles Langston (Memphis)
Nadia Lapusta (Caltech)
Winnie Lau (UC Berkeley )
Martin Lawrence (BC Hydro)
Thorne Lay (UCSC)
Jui-Chi Lee (Virginia Tech)
Duo Li (LMU)
Xian Li (Michigan)
Yuexin Li (UC Berkeley)
Lee Liberty (Boise State)
Fan-Chi Lin (Utah)
Guoqing Lin (U Miami)
Yen-Yu Lin (National Central, Taiwan)
Eric Lindsey (New Mexico)
Carlos Lozano (U Santander UDES)
Haipeng Luo (U Victoria)
Karen Lythgoe (Earth Obs Singapore)
Philip Maechling (SCEC/USC)
M.Beatrice Magnani (SMU)
Paul Martin Mai (KAUST)
Sean Malloy (UNAVCO)
Doerte Mann (UNAVCO)
Reza Mansouri (Persian Gulf U)
Chris Marone (Penn State)
Jesse N Marquez (Citizens Coalition)
Patricia Martínez-Garzón (GFZ Potsdam)
Glen Mattioli (UNAVCO)
Eric Matzel (LLNL)
Jeremy Maurer (Missouri U)
Danny Maury (MAHUR SAC)
Jeffrey McGuire (USGS)
Timothy Melbourne (CWU)
Diego Melgar (Oregon)
Davi Mencin (UNAVCO)
Raul Benjamin Mendoza (Philippines)
Haoran Meng (UCSD)
Lingsen Meng (UCLA)
Pnina Miller (PASSCAL)
Chris Milliner (Caltech)
Kami Mohammadi (Caltech)
Saeed Mohanna (UCLA )
Mohammad Mohseni Aref (Potsdam)
Hector Mora-Paez (GS of Colombia)
Halle Morrison (Malcolm X)
Reza Mortezaie (Caltrans)
Morgan Moschetti (USGS)
Taimi Mulder (NRCan)
Derrick Murekezi (Georgia Tech)
Jessica Murray (USGS)
John Nabelek (Oregon State)
Shahryar Nadr Mohammady (Water & Sewage Co)
Josie Nevitt (USGS)
Tyler Newton (U Oregon)
Craig Nicholson (UCSB)
Edwin Nissen (Victoria)
Gabriela Noriega (SCEC/USC)
David Nutakor (RTBLM)
Tara Nye (U Oregon)
Ryo Okuwaki (Uni Tsukuba)
David Oglesby (UC Riverside)
Lani Oncescu (Kinemetrics)
John Orcutt (SIO/UCSD)
Michael Oskin (UC Davis)
Abayomi Osotuyi (USTCi, China)
Makoto Otsubo (GS of Japan)
Alba Rodriguez Padilla (UC Davis)
Grace Parker (USGS)
Tim Parker (Nanometrics)
Anupam Patel (IIT Dhanbad)
Jason Patton (CGS)
Edric Pauk (USC/SCEC)
Zhigang Peng (LSU)
Patricia Persaud (LSU)
Arben Pitarka (LLNL)
Kaushik Pradhan (IISER Kolkata)
Erina Prastyani (Uppsala)
Beth Pratt-Sitaula (UNAVCO)
Germán Prieto (Nacional Colombia)
Veronica Prush (McGill)
Christine Puskas (UNAVCO)
Lei Qin (USC)
Hongrui Qiu (Rice)
Santiago Rabade (Utah)
Erik Ramirez (Caltech)
Ze'ev Reches (Oklahoma)
Carlos Reinoza (CICESE)
Hannah Reinhard (Oregon State)
Nadine Reitman (USGS)
Ludovic Ricard (CSIRO)
Sebastian Riquelme (NSC)
Arthur Rodgers (LLNL)
Zachary Ross (Caltech)
Kenny Ryan (Air Force)
Korbinian Sager (Brown)
Amir Salaree (Michigan)
Nooshin Saloor (Michgan State)
Mustafa Saribudak (Envir Geophys)
Vince Sassard (Utrecht)
Heather Savage (UCSC)
Kate Scharer (USGS)
Peter Schearer (UCSD)
Susan Schwartz (UCSC)
Chelsea Scott (ASU)
Heather Shaddox (UCSC)
Daya Shanker (IIT Roorkee)
Pieter-Ewald Share (Oregon State)
Yogendra Sharma (BITS, India)
David Shelly (USGS)
Weisen Shen (Stony Brook)
Yixiao Sheng (ISTerre)
Manoochehr Shirzaei (Virginia Tech)
Srisharan Shreedharan (UTA/PennState)
Krittanon Sirorattanakul (Caltech)
Bridget Smith-Konter (Hawaii)
Ravi Sriwastav (IIT Gandhinagar)
Jamison Steidl (UCSB)
Joann Stock (Caltech)
Wei-Fang Sun (National Dong Health)
Justin Sweet (IRIS)
Taka'aki Taira (UC Berkeley)
Nikolaos Tavoularis (RAA, Greece)
Corina Tecu (OIQ)
Prithvi Thakur (Michigan)
Nikolaos Theodoulidis (ITSAK)
Valerie Thomas (USGS)
Clifford Thurber (Wisconsin)
John Townend (Victoria)
Daniel Trugman (UT Austin)
Victor Tsai (Brown)
Jay Tung (Wisconsin)
Fatih Turhan (KOERI)
Sirena Ulloa (CSUN)
Frank Vernon (UCSD)
John Vidale (USC)
Lara Wagner (Carnegie Inst for Sci)
Robert Walker (U at Buffalo)
Christian Walls (UNAVCO)
Kang Wang (UC Berkeley)
Xiaoyu Wang (Rice)
Yongfei Wang (USC)
Shimon Wdowinski (Florida Int'l)
Max Werner (Bristol)
Chesley Williams (RMS)
Tom Williams (Citizens Coalition)
Bob Woodward (IRIS)
Lindsay Worthington (New Mexico)
Zhuohui Xiao (Michgan State)
Yuqing Xie (UCLA)
Liuwei Xu (UCLA)
Shiqing Xu (SUSTech)
Xiaohua Xu (SIO/UCSD)
Xiaotao Yang (Purdue)
Alan Yong (USGS)
Clara Yoon (USGS)
Congcong Yuan (Harvard)
Sang-Ho Yun (JPL)
Guang Zhai (Virginia Tech)
Weiwei Zhan (Clemson)
Weiwei Zhan (Tufts)
Zhongwen Zhan (Caltech)
Hao Zhang (USC)
Jiewen Zhang (Oklahoma)
Yingfeng Zhang (CEA, China)
Yingcai Zheng (U Houston)
Wenlu Zhu (U Maryland)
Xinxiang Zhu (NCALM)
Robert Zinke (JPL)
Alon Ziv (Tel Aviv)
Alan Zuñiga (USC)

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