Fault2SHA Learning Series – Coulomb Stress Transfer by Ross Stein

Earthquakes Converse by the Transfer of Stress

Ross S. Stein

Cofounder and CEO, Temblor, Inc., Adjunct Professor of Geophysics, Stanford University, Former Senior Scientist, U.S. Geological Survey

Monday 12th April 2021 15:00 Central European Time

I will argue that large earthquakes can promote and inhibit failure on nearby faults, and that the transfer of Coulomb stress plays a governing—but not exclusive—role in this interaction. Through a series of physical demonstrations and animations, I will use these concepts to explain the distribution of mainshocks, aftershocks and progressive earthquake sequences in a number of cases around the world.

In this talk, I will be conveying work of my spectacular collaborators, Geoffrey King, Shinji Toda, Jian Lin, Tom Parsons, Jim Dieterich, Keith Richards-Dinger, Aykut Barka, and Volkan Sevilgen, as this has always been a team effort, bringing together a range of insights and skills.

At heart, we find that the stress imparted by earthquakes does not simply turn seismicity on or off; rather, the background seismicity rate is enhanced by stress increases, and suppressed by stress decreases. This, we believe, best explains why seismicity in stress trigger zones is often patchy or discontinuous; why seismicity rate declines in stress shadows can be subtle or absent, and why some aftershock zones expand, migrate or densify over time, and why some aftershocks last for years and others persist for centuries.

While this model is a far cry from an earthquake prediction, it perhaps can take us on the road to the more useful and accurate earthquake forecasts that we all seek.

Image from Stein (2003)

Youtube link for those of you who missed the session (or if you want to watch again)

Fault2SHA Learning Series – Fault displacement hazard by Paolo Boncio

Fault displacement hazard – a geological perspective

Paolo Boncio

Associate Professor, DiSPUTer Department, Università degli Studi G. d’Annunzio Chieti e Pescara, Chieti, Italy

Monday 8th March 2021, 15:00 Central European Time

Fault displacement hazard (FDH) is a localized hazard due to rupture of the ground surface from slip along an earthquake fault (and fault creep). This might offset, tilt, warp and damage buildings and facilities sited across or in the vicinity of the fault trace. FDH is particularly relevant for distributed infrastructures (e.g., lifelines) and critical facilities (nuclear facilities, dams, etc.).

The seminar will focus on coseismic (not creep) FDH, in particular on 1) basic concepts, definitions, controlling factors, scale of the problem; 2) mitigation strategies based on zoning and avoidance, regulated by specific rules or guide lines; and 3) poorly known, developing methodologies based on probabilistic approaches, with examples from the globe and from Italy.

If you missed the seminar, you can watch on youtube:

https://www.youtube.com/watch?v=Qlpl8Znx8Ac

Fault2SHA Learning Series – Palaeoseismic studies in hazard modelling by Francesca Cinti

Palaeoseismic studies in hazard modelling

Francesca Cinti

Istituto Nazionale di Geofisica e Vulcanologia, Sezione di Roma 1,

Monday 22nd February 2021, 15:00 Central European Time

Among the geologic data, the trenching records of paleoearthquakes represent an important input for the development of seismic hazard evaluations and, specifically, for the characterization of fault rupture behavior in time. In this lecture I will introduce 1. the basic concept of paleoseismology, the evaluation methods and variability of fault parameters, 2. a paleoearthquake database as input for producing rupture scenarios, explore fault behavior and earthquake recurrence in Central Apennines.

Zoom link:

https://ucl.zoom.us/j/95536222190?pwd=TGNLcFhLcWpOODYxaDZramhHNHVSZz09

Youtube link if you missed the live session:

Fault2SHA Learning Series – Cosmogenic nuclides as a tool to constrain rates of deformation by Lucilla Benedetti

Cosmogenic nuclides as a tool to constrain rates of deformation

Lucilla Benedetti

CEREGE-CNRS, Aix en Provence, France

11th January 2021 15:00 Central European Time

The use of cosmogenic nuclides has revolutionized the quantification of fault motion by filling a critical gap between short-term geodetically recorded slip-rates and geological-long term- slip rates. In this lecture I will present 1-the important aspects to be understood when dealing with cosmogenic nuclides from sampling strategy to getting exposure ages, 2-several applications such as the use of depth profiles to date the emplacement of morphological surfaces, fault scarp dating to unravel past seismic events, relief building and denudation rates, and a novel application on triangular facet to assess normal fault slip-rates.

Youtube link for a recording of this event

19/11/202005/02/2021

Fault2SHA Learning Series

We are excited to announce the launch of the Fault2SHA Learning Series.

Starting in January 2021, at 15:00 (Central European Time) on the second Monday of each month, we will be hosting the Fault2SHA Learning Series.

The purpose of this series is to facilitate collaborations across different disciplines through assisting learning. This will be achieved by sessions providing a lecture comprising an overview of a selected topic relating to utilising fault data in seismic hazard assessments or a hands-on exercise on relevant open-access tools.

The sessions will be done via zoom, with the session recorded for youtube (when the lecturer or convenor gives permission).

We will be addressing topics requested in the registration forms for the Fault2SHA 5th Workshop and further topics identified in the future.

The first three lectures will be on the following subjects:

Monday 11th January: Cosmogenics by Lucilla Benedetti

Monday 22nd February: Palaeoseismic studies in hazard modelling by Francesca Cinti

Monday 8th March: Fault displacement hazard – a geological perspective by Paolo Boncio

We thank the speakers in advance for their talks.