Earthquake Environmental Effects (EEE) have proven to be valuable for describing past earthquakes and their geological imprints. The ESI2007 is a relatively new intensity scale dedicated to such effects, but also integrating traditional macroseismic scales. Examples of ESI2007 intensities assigned to large earthquakes are being collected in the EEE web catalogue hosted by the ISPRA and ESI2007-related work is conducted in the framework of INQUA.
Another milestone now has been achieved with the ISPRA volume “Earthquake Environmental Effect for seismic hazard assessment: the ESI intensity scale and the EEE Catalogue”. This book is now available online here. It contains updates on the ESI2007, examples of applications, documentation of the EEE Android App, a huge reference list and, most importantly, the ESI2007 description in ten languages: more
Our colleagues in Belgium have reasons to celebrate! At the Membach station they’re monitoring seismic activity for 40 years now, and 20 years ago the superconducting gravimeter started working. To commemorate this the Royal Observatory of Belgium and the Public Services of Wallonia organize a scientific workshop on Earthquake activity and hazard in northwest Europe. The workshop will be held on 15 October 2015 at the Gileppe Dam Tower.
In the last two posts I have reported on the scientific sessions of the Fucino15 conference and on the first of the field trips. This post is about the L’Aquila field trip. I haven’t been to this city before and I was curious to see the place that sadly became so famous in earthquake science. I was surprised by how many heavily damaged buildings were still standing and by the overwhelming amount of historical buildings that await their reconstruction. We were given a great tour through the Palazzo Ardinghelli which is currently being rebuilt, then we had a look at the worst-affected parts of the city. Here’s a report in images. more
Last Friday the RAS held a discussion meeting on Tectonics from Above: Recent Advances in the Use of High-resolution Topography and Imagery in London. Almost the entire Cambridge Tectonics Group went there and I absolutely enjoyed the meeting and the discussion with friends and colleagues mainly from the UK and from France. The speakers reported on open-source software for producing high-res DEMs, advances in aerial and satellite imagery, new techniques in remote sensing, and latest developments in fault/offset mapping. The meeting was supported by NERC, COMET+ and LICS. more
Karachi is the most populated city in Pakistan with around 24,000,000 inhabitants – just as many as Australia. Since many years a nuclear power plant (NPP) is located just a few miles outside the city at the shore. Ongoing work on new reactors with Chinese help has recently sparked outrage and media coverage. Concerns are that any accidents at the NPP might have dramatic consequences and threaten millions of people. I searched the recent scientific literature on seismic and tsunami hazard for Karachi…
On 28 February, an earthquake of MW4.4 occurred in the Fucino Basin in Central Italy. The event did not cause any damage and was not widely felt. Such an earthquake is nothing special for this area, but it’s interesting because from 19-24 April the 6th INQUA meeting on paleoseismology will be held in Pescina. The conference will bring together scientists from all around the world to discuss latest developments in active tectonics, paleoseismology and similar topics, and its date and location were chosen to commemorate the devastating Fucino earthquake of 1915. This quake left more than 33,000 people dead and was one of the largest earthquakes to hit the Mediterranean in modern history. It was also subject to a number of paleoseismological studies (see links below). more
Spain may not be as famous for its earthquakes as Greece, Turkey or Italy, but significant events do shake the western part of the Mediterranean, too. Numerous paleoseismological and archaeoseismological studies as well as research on historical quakes have been undertaken on the Iberian peninsula. A new book was now published by the IGME which collects all the information currently available on the geological effects of earthquakes in Spain. The book is in Spanish and available for free download here:
The catalogue includes 44 quakes between 218 BC and AD 2011.
Our colleague Tim Dawson from the California Geological Survey (CGS) pointed me to this website, where reports and data on the Napa Earthquake of 24 August, 2014, are collected. There is a new document available for download, the EERI report at the top of the page, which adds some previously unpublished information, especially on the observed afterslip. Tim writes that “afterslip along the central 6-7 km of the rupture is about 35 cm (whereas it was initially only about 20 cm the day of the earthquake).” The afterslip seems to be still ongoing and is monitored with InSAR. more
“Each of us has to decide what the right balance is between being effective and being honest.”
I was thinking of this quote whilst listening to Mustapha Meghraoui’s talk during this week’s ISEMG conference in Mugla (Turkey). Mustapha was reviewing the seismic hazard potential of the northern stretch of the Dead Sea Rift, and he ended by identifying two prominent areas where there was a substantial long-term (1000 yr) slip deficit that strongly suggested heightened future earthquake potential. The quote above has nothing to do with earthquakes. Neither is it by Mustapha. Instead, it relates to global warming and was from the climate modeller and policy advocate Stephen Schneider. Nevertheless, it struck me that what Schneider was wrestling with a decade or so ago with climate change has parallels to what some earthquake geologists are wrestling with now: what do we do when we believe that the science demands action? more
The 2011 Christchurch earthquake series had severe consequences and surprised scientists for many reasons. Ground motions were extremely strong despite the relative moderate magnitudes of the quakes (MW 5.3-7.1). The events happened on a system of hitherto unknown faults, some of which are located directly below Christchurch. Earthquake environmental effects (EEE), especially liquefaction, were intense and widespread. It turned out that subsequent quakes reactivated the same feeder dikes of sand blows, showing that saturated sediments are susceptible of liquefaction no matter if they had been liquefied recently (also see the paper of Quigley et al. (2013) on the liquefaction effects). Another stunning lesson was the occurrence of intense rockfall in the vicinity of Christchurch. In a recently published study, Mackey and Quigley (2014) dated rockfall boulders with 3He and show that they allow to estimate the recurrence intervall of local seismic events like the 2011 series. This works is a very interesting way to use EEE for paleo-earthquake studies. more