Posts in the category »  Opinion «  ( 15 Posts )

  • 2023 trenchiest trench photos

    The year 2023 saw devastating earthquakes occurred in Turkey-Syria and Morocco, which caused thousands of victims and heavy destruction. This post is going to have an ironic tone, but we should not forget that our duty as paleoseismologists is to provide to policymakers and society the means to take the best informed decisions.

    Usually, we do it by digging paleoseismic trenches and analyzing what they uncover. The 2023 trenchiest trench picture was posted on X (former Twitter) by Gülsen Uçarkuş, showing their trench cut into half by surface faulting following the Turkey-Syria earthquakes.

    Twitter

    By loading the tweet, you agree to Twitter’s privacy policy.
    Learn more

    Load tweet

    Trench with a view

    Paleoseismology can bring you to wonderful places:

    Twitter

    By loading the tweet, you agree to Twitter’s privacy policy.
    Learn more

    Load tweet

    Twitter

    By loading the tweet, you agree to Twitter’s privacy policy.
    Learn more

    Load tweet

    Twitter

    By loading the tweet, you agree to Twitter’s privacy policy.
    Learn more

    Load tweet

    Twitter

    By loading the tweet, you agree to Twitter’s privacy policy.
    Learn more

    Load tweet

    Twitter

    By loading the tweet, you agree to Twitter’s privacy policy.
    Learn more

    Load tweet

    The devil is in detail

    By simply looking at pictures, one can learn a ton from different styles and habits. And discover unusual expedients.

    Twitter

    By loading the tweet, you agree to Twitter’s privacy policy.
    Learn more

    Load tweet

    Twitter

    By loading the tweet, you agree to Twitter’s privacy policy.
    Learn more

    Load tweet

    Twitter

    By loading the tweet, you agree to Twitter’s privacy policy.
    Learn more

    Load tweet

    Twitter

    By loading the tweet, you agree to Twitter’s privacy policy.
    Learn more

    Load tweet

    Twitter

    By loading the tweet, you agree to Twitter’s privacy policy.
    Learn more

    Load tweet

    Twitter

    By loading the tweet, you agree to Twitter’s privacy policy.
    Learn more

    Load tweet

    Twitter

    By loading the tweet, you agree to Twitter’s privacy policy.
    Learn more

    Load tweet

    Shapes

    Trenches come in all sorts of sizes and shapes:

    Twitter

    By loading the tweet, you agree to Twitter’s privacy policy.
    Learn more

    Load tweet

    Twitter

    By loading the tweet, you agree to Twitter’s privacy policy.
    Learn more

    Load tweet

    Twitter

    By loading the tweet, you agree to Twitter’s privacy policy.
    Learn more

    Load tweet

    Trench mindfulness

    Trenching team mandatory equipment: foldable chair or any other object suitable for sitting on it and sketching the trench log.

    Twitter

    By loading the tweet, you agree to Twitter’s privacy policy.
    Learn more

    Load tweet

    Twitter

    By loading the tweet, you agree to Twitter’s privacy policy.
    Learn more

    Load tweet

    Twitter

    By loading the tweet, you agree to Twitter’s privacy policy.
    Learn more

    Load tweet

    Holy cow! (and other animals)

    If only the students attending my lessons were interested in my slides like these animals are in trenches…

    Twitter

    By loading the tweet, you agree to Twitter’s privacy policy.
    Learn more

    Load tweet

    Twitter

    By loading the tweet, you agree to Twitter’s privacy policy.
    Learn more

    Load tweet

    Twitter

    By loading the tweet, you agree to Twitter’s privacy policy.
    Learn more

    Load tweet

    Twitter

    By loading the tweet, you agree to Twitter’s privacy policy.
    Learn more

    Load tweet

    Not surprising that cows are supervising trench excavations.

    Twitter

    By loading the tweet, you agree to Twitter’s privacy policy.
    Learn more

    Load tweet

    Excavator operator shout-outs

    They are often underappreciated but are a fundamental component for a good result!

    Twitter

    By loading the tweet, you agree to Twitter’s privacy policy.
    Learn more

    Load tweet

    Twitter

    By loading the tweet, you agree to Twitter’s privacy policy.
    Learn more

    Load tweet

    Twitter

    By loading the tweet, you agree to Twitter’s privacy policy.
    Learn more

    Load tweet

    Hand-dug trenches shout-outs

    For the bravest only:

    Twitter

    By loading the tweet, you agree to Twitter’s privacy policy.
    Learn more

    Load tweet

    Twitter

    By loading the tweet, you agree to Twitter’s privacy policy.
    Learn more

    Load tweet

    No caption

    Twitter

    By loading the tweet, you agree to Twitter’s privacy policy.
    Learn more

    Load tweet

    If you enjoyed this post, don’t buy me a coffee – I’m already caffeine-addicted. On the contrary, please go and make your workplace a better one: be kind to your peers, don’t put pressure on the students you’re supervising or don’t stress the hell out of your supervisor!

  • Trenching season is ongoing!

    Following an un-systematic post-dinner doomscrolling I’m happy to declare May 2022 as the trenchiest month ever. Here’s some exhibits:

    Safety first; if cozy and comfy it’s better.

    The award goes to Stéphane Baize (@Stef_EQ_Geology) and their trenches along the Cévennes fault: look at the details in the photo… like “paleo” engraved in the wooden frame to prevent collapse of the trench wall. And what about the tent? 10/10 professional style.

    Twitter

    By loading the tweet, you agree to Twitter’s privacy policy.
    Learn more

    Load tweet

    Landscape photography award

    The winner is Colca Canyon in Southern Peru, take a look at the pictures by Anderson Palomino (@AndersonRPT1) and Carlos Benavente (@clbenavente)

    Twitter

    By loading the tweet, you agree to Twitter’s privacy policy.
    Learn more

    Load tweet

    Twitter

    By loading the tweet, you agree to Twitter’s privacy policy.
    Learn more

    Load tweet

    Best flower structure award

    No doubts here, easy win for Ian Pierce (@neotectonic) and their trenches in Azerbaijan. Follow him for stunning field photos and videos.

    Twitter

    By loading the tweet, you agree to Twitter’s privacy policy.
    Learn more

    Load tweet

    Mud club

    Mention goes to Jade Humprey (@ForFaultsSake).

    Twitter

    By loading the tweet, you agree to Twitter’s privacy policy.
    Learn more

    Load tweet

    The tricks of the trade.

    Learn them from Jonathan Obrist-Farner (@guateologist) uncovering the mysteries of the 1976 Motagua rupture in Guatemala

    Twitter

    By loading the tweet, you agree to Twitter’s privacy policy.
    Learn more

    Load tweet

    Category “You don’t need a trench to find good stratigraphy”.

    Prize goes to Gabriel Easton Vargas (@geastonvargas) and paleotsunami research in semiarid Chile

    Twitter

    By loading the tweet, you agree to Twitter’s privacy policy.
    Learn more

    Load tweet

    Category “Let’s the student do the work”.

    Terrific exhibit by Shreya Arora (@shryaarora) trenching in the Himalaya region

    Twitter

    By loading the tweet, you agree to Twitter’s privacy policy.
    Learn more

    Load tweet

    Never without a nijiri gama.

    Award is won by Sambit Prasanajit (@SPrasanajit) and their sites in S. Korea

    Twitter

    By loading the tweet, you agree to Twitter’s privacy policy.
    Learn more

    Load tweet

    Fancy fence

    The winner is PhD student Argelia Silva Fragoso (@Argy_sf) from Insubria university, digging trenches in Central Italy

    Twitter

    By loading the tweet, you agree to Twitter’s privacy policy.
    Learn more

    Load tweet

    Sorry if I missed someone, I wish you all a safe and fruitful field season!

  • Paleoseismology & the new Hungarian NPP Paks II

    Hungary plans to build a new nuclear power plant (NPP) at the banks of the Danube near Paks, where another NPP is already running for several decades. An interesting story is currently unfolding around the geological site conditions, and this story includes paleoseismology. In short, the Austrians and external experts argue the planned NPP Paks II will sit on a capable fault, while the Hungarians say there is a fault, but it can’t rupture the surface. Actually, it’s a bit more complicated…

    more
  • How common are fault re-ruptures?

    Five years ago, on October 30, 2016, a Mw 6.5 earthquake nucleated along the Vettore Fault in Central Italy.

    This event is particularly interesting because its surface rupture overprinted the faulting occurred only 3 months earlier, on August 24. In the last 5 years, at least 2 other cases of repeated rupture in a short time interval were observed, i.e., the 2016 Kumamoto (Japan) and 2019 Ridgecrest (US) sequences.

    Fault re-ruptures are currently not accounted for in seismic hazard assessment; should paleoseismology folks care about re-ruptures? To answer this question, it is necessary to understand how common re-ruptures are.

    So, I checked the USGS catalogue, looking for earthquakes with M > 6, depth < 30 km occurred since January 1st, 2016. I chose these thresholds because I’m interested in surface-rupturing events, but maybe the values need some fine-tuning. The search returns 490 earthquakes. Then, I filter out events with epicenters offshore, since surface faulting is more difficult to document there. A total of 104 earthquakes (21% of the total) occurred onshore (Figure 1).

    Figure 1: map of onshore and offshore earthquakes (M > 6, z < 30 km) occurred since 2016. Data source: USGS catalogue.

    Figure 2a shows the distribution of the 104 earthquakes according to magnitude (bin size 0,2 magnitude units). Now I calculate the expected number of surface-rupturing events, using the probability curves provided by Youngs et al. (2003; their Equation 4) and shown in Figure 2b. Out of the 104 earthquakes, it can be expected that 63 should have produced surface faulting.

    Figure 2: a) distribution of the onshore earthquakes, bin size 0,2 magnitude units; b) probability of surface rupture as a function of magnitude.

    Finally, let’s check how many re-ruptures have been actually observed: as mentioned earlier, they are at least Kumamoto, Ridgecrest and Central Italy. Three out of 63 means that ca. 5% of the shallow M > 6 earthquakes onshore include the repeated rupture of the same fault strand(s).

    This has strong implications for paleoseismology, because it is virtually impossible to identify events occurring few months or years apart. In turn, this may affect the computation of key parameters for seismic hazard assessment, such as recurrence interval, slip per event and elapsed time.

    These ideas are at the core of a project I’m writing right now, called REDEFINE: “RE” stands for re-rupture and Task 1.1.3 will be the update of the probability curves of Figure 2b – no more spoiler on the project!

    If I’ll get that 1 million €, you’ll hear more on re-ruptures from me 😊

     

     

     

  • Soft-sediment deformations buried beneath the center of the Dead Sea record hundreds of large earthquakes spanning the past 220,000 years

    1. Key points

    This is the first attempt to apply a computational fluid dynamic modeling-based quantitative “fossil seismograph” to develop a large earthquake record.

    The record is calibrated to historic earthquakes, for which the Dead Sea area has a famously long span, and it confirms a clustered earthquake recurrence pattern and a group-fault temporal clustering model.

    The record yields much shorter mean recurrence for large (≤ 1.4 kyr vs. 7-11 kyr) and moderate (≤ 500 yr vs. 1600 yr) earthquakes than previously obtained, thus reveals a much higher seismic hazard than previously appreciated on this slow-slipping plate boundary.

    more
  • My top ten list of earthquake blogs

    I am running this blog for more than five years now and it is time to acknowledge the other geo-blogs out there that have inspired me. In order to stay updated I follow the Geobulletin, which monitors the geoblogosphere activity. There are numerous amazing blogs out there that are either fun to read or interesting or both, but here I will focus on the ones dealing with earthquakes/tectonics/geomorphology/tsunamis. Here is my personal, subjective, but honest, list of earthquake blogs that I like and read: more

  • A new Nuclear Power Plant near Karachi

    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…

    more

  • World Heritage Site unacceptably damaged: Nazca Lines, Peru

    Never, never, never ever, for no reason it is justifiable to damage a cultural heritage site. Not in Peru, not anywhere else in the world. Never. It should be always one of our primary objectives to sustain cultural and natural heritage sites. No discussion.

    more

  • Earthquake in Pakistan – lessons to learn

    After the strong earthquake in Pakistan a good part of the media coverage was about the fascinating story of the new island that emerged off Gwadar. While this was really amazing I think now it’s time to think about the consequences of the quake itself. We have seen a shallow M7.7 event that produced severe shaking across a large area. Peak ground acceleration exceeded 1 g in the 0.3 s period and was still intense in longer periods. 515 people have reportedly been killed and more than 100,000 are homeless. more

  • A mud volcano as an Earthquake Environmental Effect?

    On 24 September a shallow M7.7 earthquake rattled Pakistan. At least 300 people died and thousands of houses, most of them adobe, collapsed in Balochistan Province. The quake was felt as far away as Muscat (Oman) and New Delhi (India). Epicentral intensities reached up to IX. The earthquake appeared to be a strike slip event. Soon the media reported on an amazing effect of the quake – in roughly 400 km distance a new island appeared few hundred meters off Gwadar. more