Special issue on sub-aquatic paleoseismology

A special issue on sub-aquatic paleoseismology has been published in Marine Geology. The volume 384 ‘Subaquatic paleoseismology: records of large Holocene earthquakes in marine and lacustrine sediments‘ collects papers on marine and lacustrine mass movements that can be used to decipher the earthquake history. The contributions span a wide range of different settings, from the famous Cascadia sites to Greece, and are based on presentations from the International Sedimentological Congress in Geneva (August 2014) and the AGU Fall Meeting in San Francisco (December 2014). Continue reading “Special issue on sub-aquatic paleoseismology”

Minoan Earthquakes: Breaking the Myth through Interdisciplinarity

In a recent post on this forum, Angela Landgraf shared a digest of the long and winding road having led to the publication of Seismicity, Fault Rupture and Earthquake Hazards in Slowly Deforming Regions. Reading this post in the midst of wrapping up the edition of our Minoan Earthquakes volume, I could only sympathize with her concerns and hopes for the future of edited books at a time when impact factors and other author-level metrics all too often dictate academic choices.

Four years and a half (!) after the Out of Rubble Leuven workshop (29-30 November 2012), we are proud to announce the publication of Minoan Earthquakes: Breaking the Myth through Interdisciplinarity at Leuven University Press. Reasons for such delay are manifold but chief among them is our editorial choice of producing a coherent volume that might be used as an up-to-date toolbox for readers interested in the broader field of archaeoseismology – not just Minoan archaeoseismology – and its (necessary) relationship to other, better established, disciplines. This choice is reflected by the structure of the book and breadth of topics covered by its authors, ranging from seismology, paleoseismology, geophysics, architecture, engineering and, of course, Minoan archaeology. Although we will ultimately leave readers to judge how successful we were in this endeavor, we are encouraged by Iain Stewart’s appreciation of the volume: Continue reading “Minoan Earthquakes: Breaking the Myth through Interdisciplinarity”

Use late-Holocene tidal notches as earthquake geological effects?

Tidal notches are a generally excepted sea-level marker. Particularly in the Mediterranean, those shoreline indicators are oftentimes used to infer coastal coseismic activity when they occur displaced from present day sea-level. Now, paleoseismologists should be able to visualize coastal evolution in order to better understand coseismic history. Continue reading “Use late-Holocene tidal notches as earthquake geological effects?”

Paper: Using georadar and a mobile geoelectrics device to map shallow sediment distribution on a large scale

[UPDATE 2017-05-14: The links now lead to the free version of the paper, available until 30 June.]

Together with my colleagues I have published a new paper in which we describe a methodology for mapping the shallow architecture of large sedimentary basins with minimum effort and high resolution. We use two geophysical methods and combine them with point information from shallow drillings to identify different types of alluvial, fluvial, and aeolian sediments in the Orkhon Valley in Mongolia. We then show that our results fit well with a remote sensing approach. Although we did not target active faults in our study, the methodology is well suitable for detecting deformed/offset sediments without surface expression due to high erosion or sedimentation rates. That’s why I feel the study is of interest for the fault-hunting community. Continue reading “Paper: Using georadar and a mobile geoelectrics device to map shallow sediment distribution on a large scale”

New papers on paleoseismology, tsunami, and active tectonics (May 2017)

It’s just a few months after the Kaikoura earthquake and now the first papers have been published already. Today’s paper round-up also includes studies on dating tsunami boulders, turbidite paleoseismology, paleoseismology in the Tien Shan, the recent Italy and New Zealand earthquakes, and earthquakes and social media. Enjoy reading! Continue reading “New papers on paleoseismology, tsunami, and active tectonics (May 2017)”

Paper: Post-seismic deformation reveals a significant seismic hazard is still present at Bam (Iran)

In 2003 a devastating Mw 6.6 earthquake shook the city of Bam in the remote Kerman region of SE Iran, killing at least 31,000 people. This was one of the most destructive earthquakes on record in Iran, and racked up the fifth largest death toll of any earthquake since the year 2000. This blog post will focus on highlighting research which shows that even after this awful natural disaster, the hazard posed by faults in the area is likely to have remained high, contrary to many common assumptions.

Immediately following the Bam earthquake scientists scrambled to map the housing damage, surface fractures, aftershock patterns and co-seismic deformation to better understand the earthquake source [1][2]. One such study found that the structure responsible for the extreme shaking  at Bam was a previously unrecognised near-vertical strike-slip fault directly beneath the city, which ruptured between 2-8 km depth [3]. However, accurate aftershock locations suggested that the fault zone could generate earthquakes well below the base of the 2003 rupture patch, to nearly 20 km depth [4].

Slip distribution during the 2003 Bam earthquake and the associated aftershocks (white circles). The aftershocks are clearly occurring below the co-seismic rupture, suggesting the bottom half of the fault is seismogenic and unruptured.
Slip distribution during the 2003 Bam earthquake and the associated aftershocks (white circles). The aftershocks are clearly occurring below the co-seismic rupture, suggesting the bottom half of the fault is seismogenic and unruptured.

The observation that only part of the seismogenic layer at Bam had ruptured in 2003 posed a series of important questions for the future seismic hazard in this already fragile region:

(1) Will post-seismic deformation mechanisms relax the stress changes generated by the 2003 earthquake on the fault surface aseismically?

(2) What is the future seismic hazard at Bam?

In a recent paper published in Geophysical Journal International, we have addressed these questions, as well as other topics of academic interest, by studying the post-seismic deformation after the Bam earthquake [5].

Continue reading “Paper: Post-seismic deformation reveals a significant seismic hazard is still present at Bam (Iran)”

New papers on paleoseismology, tsunami, and active tectonics (Apr 2017)

Today in the paper round-up (April 2017): Active Tectonics of the Makran, postseismic deformation at Bam, active faults and paleoseismology in Italy, Switzerland & Alaska, the first papers on the Kaikoura earthquake, tsunamis in Chile and the Western Mediterranean, and faults in Mexico. Enjoy reading! Continue reading “New papers on paleoseismology, tsunami, and active tectonics (Apr 2017)”

Call for contributions to textbook ‘Structural Geology and Tectonics: Problems and Solutions’

Our colleague Åke Fagereng from Cardiff University will edit a textbook on problems in structural geology and tectonics together with Soumyajit Mukherjee and Andrea Billi. The editors invite contributions from the tectonics community. Perhaps you have a nice active tectonics exercise to share? Here is the announcement: Continue reading “Call for contributions to textbook ‘Structural Geology and Tectonics: Problems and Solutions’”

Call for papers: TECTONICS Spec. Iss. “The 2016 Central Italy Seismic Sequence: Insights, implications and lessons learned”

Our colleague Lucilla Benedetti (CEREGE, France) distributed the following call for papers on the recent earthquake series in Central Italy:

Dear Colleagues,

We would like to invite contributions to a special volume entitled « The 2016 Central Italy Seismic Sequence: Insights, implications and lessons learned » that will be published in Tectonics AGU journal (details here).

Continue reading “Call for papers: TECTONICS Spec. Iss. “The 2016 Central Italy Seismic Sequence: Insights, implications and lessons learned””