New papers on paleoseismology, tsunami, and active tectonics (Feb 2016)

Here’s the February edition of my paper recommendations. This time we have:

  • Paleoseismology in Germany and Nepal (the latter with a focus on charcoal dating techniques),
  • Tsunamis in Greece, Portugal, Israel and Alaska,
  • Turbidites in Portugal,
  • New insights into the geodynamics of Mozambique,
  • Fault rheology in Iran,
  • Rupture jumps on strike‐slip faults, and
  • A MATLAB tool for seismic hazard calculations.

Enjoy!

Continue reading “New papers on paleoseismology, tsunami, and active tectonics (Feb 2016)”

IRSN report on the Napa Earthquake, California (M6, 2014-08-24)

Our colleagues Stéphane Baize and Oona Scotti from the French IRSN finished a report on the 2014 Napa Earthquake: Post-seismic survey report, with special focus on surface faulting. On 24 August 2014, an earthquake of magnitude Mw6 occurred on the West Napa Fault in shallow depth. The quake caused significant damage, an interesting pattern of surface ruptures, and the immediate attention of hundreds of geologists. The primary and secondary effects were mapped only hours after the event, which turned out to be extremely important – a large amount of afterslip was recorded in the following days. The earthquake was not only recorded by a huge seismometer network, but the ground motion was also captured by GPS sensors and InSAR images. The new IRSN report is especially concerned with the surface faulting hazard, since this agency is responsible for the safety of nuclear installations in France.  Continue reading “IRSN report on the Napa Earthquake, California (M6, 2014-08-24)”

Guest blog: “Photogrammetry for Paleoseismic Trenching” by Nadine Reitman (USGS)

Error analysis

A few weeks ago, Nadine Reitman (USGS) published an interesting paper about the use of Photogrammetry for Paleoseismic Trenching in BSSA. In this guest blog she shares her key findings and explains how to minimise errors without spending too much time measuring control points. Thanks Nadine!

Structure-from-motion (SfM) is now routinely used to construct orthophotos and high-resolution, 3D topographic models of geologic field sites. Here, we turn SfM on its side and use it to construct photomosaics and 3D models of paleoseismic trench exposures. Our results include a workflow for the semi-automated creation of seamless, high resolution photomosaics designed for rapid implementation in a field setting and a new error analysis of SfM models. Continue reading “Guest blog: “Photogrammetry for Paleoseismic Trenching” by Nadine Reitman (USGS)”

Paleoseismology & Tsunami papers – Christmas edition

This is this year’s last issue of my paper round-up, and it includes some pretty interesting stuff. Our Greek colleagues published a report on the liquefaction caused by the 2014 Lefkada earthquakes, just in time with the recent earthquake that hit more or less the same area again (Papathanassiou et al., and see earlier posts here). Long et al. published a paper on iceberg-induced tsunamis, found in the sedimentary record – that’s a great story, isn’t it? Jacobson’s PhD on the Lake Heron Fault (NZ) is an interesting read, and Iván Sunyol’s paper on paleoseismological trenches in Mexico is especially interesting for those who attended the 2012 Morelia meeting. Zhou et al. come up with a great dataset of Pléiades imagery from the El Mayor-Cucapah Quake, Calais et al. have a close look on the northeastern Caribbean, and finally, Kufner et al.’s paper is about the collision between India and Asia deep below the Pamir and Hindu Kush.

Enjoy reading and Merry Christmas!

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Guest blog by Marta Ferrater (Uni Barcelona): Lateral Offset Quality Rating along Low Slip Rate Faults

Marta Ferrater from the Universitat de Barcelona did a lot of research on the Alhama de Murcia Fault. Her most recent paper deals with how good we can measure lateral offsets along faults which move only very slowly. This is probably of great interest for many people working on slow faults, so I am glad that she agreed to write the following guest post: Continue reading “Guest blog by Marta Ferrater (Uni Barcelona): Lateral Offset Quality Rating along Low Slip Rate Faults”

A preliminary report on the 17 Nov, 2015, M6.4 South Lefkada earthquake, Ionian Sea, Greece

On 17 November, 2015, a MW6.4 strike-slip earthquake occurred in Lefkada Island, Greece. Lefkada is close to the Cephalonia Transform Fault and has repeatedly experienced strong shaking in the past. The most recent event caused two fatalitites, some damage, and resulted in widespread environmental earthquake effects (EEE). A team of scientists visited the epicentral area after the quake and recorded the damage and the EEEs. They wrote a preliminary report, which can be downloaded here: Lefkada 17 Nov 2015 earthquake report (PDF, 3.9MB).

They document mass movements, damage to buildings, and present first data from seismology, GPS and satellite geodesy.

Thanks to George for sending us the report!

 

New Paper: Paleoseismology & active tectonics in Greece, and how seismic hazard zonation fails

We published a new study dealing with paleoseismological work on the Milesi Fault near Athens, Greece. A slip rate was estimated based on GIS work, mapping, and trenching. Four surface-rupturing earthquakes in the last 4-6 ka were found, and we estimate magnitudes of around M6.2. With these input parameters, we developed a seismic hazard scenario that also takes into account site effects. Our results show that the official seismic hazard zonation in Greece, which is based on instrumental and historical records, contradicts geological data. We also show that extension in this region is not only confined to the Southern Evoikos Gulf graben system, but a significant amount of extension is accommodated by active faults closer to Athens. Continue reading “New Paper: Paleoseismology & active tectonics in Greece, and how seismic hazard zonation fails”

Neotectonics and seismic hazard of the Cusco Region, Peru

Our colleague Carlos Benavente Escóbar from the Instituto Geologico Minero Metalurgico (Peru) brought a book to my attention which was published in 2013: Neotectonics and seismic hazard of the Cusco Region. The book is in Spanish, but you will find it easy to understand what it’s about, because it is full of fascinating images of faults, fault scarps, seismites, liquefaction features, geological maps, and outcrop sketches. Have a look, it’s great! The book can be viewed online for free and is also available for download. Continue reading “Neotectonics and seismic hazard of the Cusco Region, Peru”