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It took a while, but now it’s finally here: Understanding Past Earthquakes, an open access book on the science of identifying large earthquakes. It deals with fundamental questions on large past events: Where did earthquakes occur? How large were they? Which tectonic faults caused them? How strong were the ground motions and where?
Six chapters cover the following subjects:

• Ou et al. – Earthquake Source Parameters Determination Using Analog Seismic Records
• Hough – Macroseismology
• Sintubin – Archaeoseismology: Identifying Earthquake Effects in Ancient Sites
• Zielke & Klinger – Past Earthquakes in Continental Settings—A Geomorphologic Perspective
• Philibosian – Paleoseismology and Paleogeodesy Using Coral Microatolls
• Moernaut et al. – Lacustrine Records of Past Seismic Shaking

Basically, it’s about paleoseismology, but excluding paleoseismology, because we already have McCalpin’s book. Neighbouring topics such as coseismic landslides, the ESI2007 scale, soft-sediment deformation, tsunamis, and marine turbidites have already been covered by other books or recent reviews.

The book was edited by Austin Elliott and Christoph Grützner. It’s free as a PDF or e-book, but also available as a hardcover for your bookshelf. Check it out here: https://link.springer.com/book/10.1007/978-3-031-73580-6.

This is a guest post by Szymon Świątek

New research challenges the assumption that only strong earthquakes cause liquefaction. Scientists from Poland demonstrated that even low-magnitude shocks (~M3.5) can trigger sediment deformation in water-saturated fine-grained sediments. This finding expands our understanding of seismic activity and its effects on geological structures.

– Focus: Mexican Pacific coast – Subduction Zone
– Responsibilities: Field and lab research on coastal geomorphology and tectonic deformation, or/and earthquake, and tsunami geology
– Qualifications: Recent Ph.D. in earth sciences, desirable background in either coastal geomorphology, earthquake geology, sedimentology, Quaternary dating, microfossils analytical techniques

Hey paleoseismicity nerds!

At the wonderful Inqua meeting in Rome I saw plenty of presentations and posters with trench pictures. After the first edition in 2022, it’s time to look for the trenchiest trench pictures of 2023. Here’s what you need to do:

1. Take a break from your too-serious-work
2. Open the folder with all the field photos
3. Choose the best/funniest/strangest ones
4. Smile
5. Post them on Twitter and tag @GingerFault or send me an email since the bird app is quickly agonizing.

This year categories include “trench with a view”, “the devil is in detail”, “holy cow!”, “trench mindfulness” plus other random stuff which I cannot reveal right now since I still have to figure them out.

Besides the classical paleoseismology studies in today’s list, we have some papers that deal with secondary and cascading effects of earthquakes, such as landslides and diseases, and interesting new findings on short term and long-term tectonic geomorphology. Enjoy reading!

Project EDITH runs under the umbrella of INQUA’s TERPRO commission and the Int’l Focus Group TPPT (Terrestrial Processes Perturbed by Tectonics). EDITH proposes to organize and facilitate annual meetings with a wide range of experts in earthquake geology, paleoseismology, geodesy and tectonic geomorphology to gain a better understanding of the earthquake cycle with the final aim to provide constraints for future new seismic hazard assessment (SHA) geologically-based models. The kickoff meeting has now been scheduled to 14-16 April, 2021 and will be held via Zoom.

On 23 June, 2020, a magnitude 7.4 subduction earthquake struck western Mexico and let the earthquake early warning sirens sound in the capital. Reportedly, ten people lost their lives and thousands of houses were damaged in Oaxaca. Our colleagues Magda Velázquez-Bucio, Sabina Porfido, and Alessandro Michetti have put together a report on the Earthquake Environmental Effects of this event in English and Spanish:

The recent publication of a paper on the Weitin Thrust (Papua New Guinea) by Chen, Milliner and Avouac (Fig. 1) gave me the opportunity to dig out and look back to some notes I wrote few months ago. Chen et al. use optical image correlation to document coseismic surface ruptures along the Weitin Thrust occurred in a Mw 8.0 event in 2000 and in a Mw 7.7 event in 2019. The ruptures overlap along a 20-km long portion, with 3-4 m of slip (Fig. 2).

Dear colleagues,

It is with great sadness that we received note from the passing of our dear colleague Victor Hugo Gorduño Monroy.

Victor was a close friend to many of us and an outstanding person in the Mexican scientific community. He authored a great number of publications on the geology of Mexico, on tectonics, volcanism, and hazards. His work did not only advance geosciences, but also had huge impact on society. He was tireless in helping to raise the awareness for disasters and to promote geoscience in the public. We will never forget his enthusiasm and his dedication in the field.

He had the leading role in geosciences at the Michoacan University of San Nicolás de Hidalgo and taught hundreds of students during his career.

Victor organized the first PATA days outside Europe in November 2012 in Morelia in commemoration of the 1912 Acambay Earthquake, which was an absolute pleasure and a great success.

Our thoughts are with his family and with everyone who worked closely with him.

The Michoacan University of San Nicolás de Hidalgo released the following letter of condolence:

El día de hoy sufrimos la pérdida de una de nuestras más sólidas columnas institucionales. Informamos con profunda tristeza que el Dr. Víctor Hugo Garduño Monroy falleció esta mañana y con él perdimos a nuestro Líder Académico y Fundador de la Maestría en Geociencias y Planificación del Territorio y del Instituto de Investigaciones en Ciencias de la Tierra. El Dr. Garduño fue un incansable investigador de la Geología de nuestro Estado y del Occidente de México. Formador profesional de centenares de estudiantes a nivel profesional y posgrado. Ganador de la Presea José María Morelos y Pavón y Primer Investigador en Obtener la Presea Vasco de Quiroga en nuestra querida Universidad Michoacana de San Nicolás de Hidalgo. Hoy se fue uno de los mejores investigadores de nuestra Universidad, de nuestro Estado y de nuestro País. Siempre será recordado por el cariño a su profesión, a sus estudiantes y compañeros. Descanse en Paz.

Moderate to strong earthquakes commonly produce secondary effects (landslides, liquefaction, tsunamis), which worsen the impact of the seismic event, both during the emergency and recovery phases.

Landslides can be triggered by events of M above 5 or so, and stronger events can produce thousands of landslides. Landslide inventories were compiled for dozens of events and the relations between Mw and maximum distance or area affected by landslides have been analyzed (e.g., Keefer, 1984; Rodriguez et al., 1999). On the other hand, the total area affected by landslides is one of the metrics used to assign the ESI intensity (Environmental Seismic Intensity; Michetti et al., 2007).