PhD opportunity: Holocene palaeoseismicity and sea-level change in Chile

The Department of Geography, Northumbria University, seeks to appoint a PhD student to work on Holocene sea-level change and palaeoseismicity in Chile. Funding is available to UK and international students. The closing date is 20th January 2017. Read on for more details about the position.  

A tsunami in Belgium?

In the wake of a series of devastating tsunamis in the Indian Ocean, Chile and Japan, Cecile Baeteman was asked whether such an event could also happen in the North Sea. Prof. Baeteman is an expert in sea-level change and coastal processes at the Royal Belgian Institute of Natural Sciences. Here are her thoughts on whether tsunamis pose a threat to coasts of the UK, France and, in particular, Belgium:

On this day in 1960

A sand layer deposited by the 1960 tsunami,
deposited on top of and later covered by peat

Today, 22nd May 2016, marks the 56th anniversary of the 1960 Great Chilean earthquake. With a magnitude estimated at 9.5, this still stands as the largest instrumentally documented earthquake worldwide. 

Palaeoseismologists have sought to characterise the geological evidence for this earthquake and the subsequent tsunami in a range of different settings.

A Thai field season in 90 seconds (+Video)

Kruawun Jankaew (Chulalongkorn University, Thailand), Evelien Boes (Ghent University, Belgium) and I have been exploring lakes and lowlands along the coast of Thailand for the last couple of weeks. Following on from my last post on our first couple of days, we've condensed the rest of the field season into less than 90 seconds of video...

First days of Thailand fieldwork (+Video)

Evelien Boes, Kruawun Jankaew and I are currently in Thailand looking for sedimentary evidence of the 2004 Indian Ocean tsunami.  Our main focus is on coastal lakes and we've spent the last two days exploring various potential sites around Thap Lamu, Khao Lak, Bang Sak and Kho Khao.

Here's a quick glimpse of our travels and travails so far, condensed into 36 seconds...

Thailand tsunami fieldwork

Evelien Boes and I are currently in Thailand. For the next two weeks we'll be investigating tsunami deposits in coastal locations in Phang Nga Province with Kruawun Jankaew from Chulalongkorn University. Evelien will be blogging about our trip over at the UGent Fieldbook. Her first post covers the 2004 Indian Ocean tsunami and includes some chilling videos taken in the area in which we will be working.

EGU2016: Speakers announced

We are delighted to announce that Dr Raphaël Paris (Université Blaise Pascal - Clermont-Ferrand) will be the invited speaker for the EGU 2016 session "Geological records of extreme wave events". Dr Paris will speak on "Tsunami deposits at high altitudes on the flanks of volcanic islands". 

We're also pleased to welcome Professor Ben Horton (Rutgers), who will give the Plinius Medal Lecture as part of the session. We congratulate Prof. Horton on this prestigious medal and look forward to his lecture on "The importance of sea-level research".

We are still welcoming submissions for session NH5.7/GM12.6/SSP3.20 on any aspect of extreme waves in the geological record, including field investigations, numerical and physical modelling studies and everything in-between. The abstract deadline is 13th January 2016. To submit an abstract, click on the link on the session page of the EGU website. Check out the info page for more details on how to submit. 

Vulnerable Coastal Areas

Philipp Kempf, Renard Centre of Marine Geology, Ghent University,
presents on his research into tsunamis in Chile

The Belgian Royal Academy for Overseas Sciences held a multidisciplinary workshop on Vulnerable Coastal Areas on 10th December. The workshop, chaired by Cecile Baeteman, brought together researchers from Belgium, the UK and Chile, with presentations on hazard, risk and resilience in a variety of different settings.

EGU 2016 session: Geological records of extreme wave events

Abstract submission has just opened for the 2016 European Geoscience Union General Assembly, to be held in Vienna from 17-22nd April. We invite you to submit abstracts for our session on Geological records of extreme wave events.

Magnitude 8.3 earthquake, central Chile, 16th September 2015

USGS Shakemap: available here

A great earthquake struck central Chile yesterday, with severe to extreme shaking felt in the Coquimbo region. The initial magnitude is estimated at 8.3, making this larger than the 2014 Iquique earthquake and the largest to strike Chile since the magnitude 8.8 earthquake of 2010.

The earthquake occurred along the Chilean Subduction Zone, a fault between the Nazca and South American Plates. The Nazca Plate subducts beneath South America, with the strain that accumulates over time episodically released during earthquakes. Great subduction zone earthquakes such as this are accompanied by intense shaking that may last several minutes. They also frequently generate tsunamis, which may be damaging both close to the source and across ocean basins. Wave heights of over 4m have been reported in Chile. The Pacific Tsunami Warning Centre suggests large waves are unlikely for most Pacific countries, however Chile and French Polynesia remain on alert for waves exceeding 1m.

So, what happens when a giant tsunami inundates coastal lakes?

This blog post is by Philipp Kempf, PhD student at Ghent University, who writes about his recently published Sedimentary Geology paper on tsunami deposits in coastal lakes in south central Chile. Philipp is now on twitter too, tweeting as @TsunamiPhil.

Pan Pacific Palaeoseismology symposium

Last week I was delighted to welcome fellow academics, friends and collaborators from Potsdam Universty, Ghent University, Durham University and The Geological Survey of Belgium to join me for a symposium on subduction zone palaeoseismology. The day-long meeting was an opportunity to present and discuss the different approaches that we use when studying past earthquakes, tsunamis and subduction zone behaviour.

The 1877 and 2014 earthquakes

We provided a brief introduction to the 1st April 2014 Iquique earthquake earlier. It's struck the Northern Chilean (or Iquique) seismic gap, an area that hasn't ruptured in a major megathrust earthquake since 1877 (though a magnitude 7.7 earthquake did rupture a deeper section of the interface in 2007). GPS data published in 2004 suggested the Nazca and South American plates were fully coupled, with none of the plate convergence being offset by slip between the plates. An update just last year identified three zones of high coupling - the Camarones, Loa and Paranal segments - separated by weaker zones. Potentially any of these segments would individually be capable of producing an earthquake of the size of the one seen yesterday. The authors

Magnitude 8.2 earthquake north of Iquique, Chile, April 2014

A major earthquake struck the north of Chile yesterday (1st April 2014), with intense shaking felt in the cities of Iquique and Arica. Less intense shaking was also felt across northern Chile and in Bolivia, Peru, Brazil and Costa Rica..The USGS maintains 'did you feel it?' pages, where anyone can report shaking that they have experienced. Here's the page for the 1st April earthquake: Did you feel it?. Initial reports placed the magnitude in the region of 8.0, with subsequent analysis upgrading this to 8.2. This USGS page will continue to be updated as further information on the earthquake becomes available. For comparison, the 2010 Maule (Chile) earthquake measured 8.8, the 2011 Tohoku (Japan) earthquake registered

Recent magazine article highlighting our work

While we've been busy on fieldwork and analysing the sediments we've collected, we're also keen to keep publishing our findings and updating people on where we're at with our research. Back in September our first academic paper on Chilean earthquakes was published in Quaternary Science Reviews. This month we've written an article in International Innovation magazine, produced by Research Media Ltd. The Environment issue of this magazine disseminates current global environmental issues to the wider

Coring, coring, coring (+Videos)

Much of our last field season was spent coring tidal marsh sediments. See previous posts for more details on what we do both in the field and back in the labs. In order to sample sediments several metres below the ground surface we use a sediment corer - either a gouge corer (for reasonably consolidated sediments) or a Russian corer (in peats or more unconsolidated sediments). Here is a short video showing us using a gouge corer at Chaihuin, with the invaluable help of Bill Austin from St Andrews University.

Fieldwork in photos

We're in Valdivia at the moment, which means reliable internet, something that we've been without for the last week. We've been at Pucatrihue and Llico, coring marshes in our search for evidence of predecessors of the 1960 Chilean earthquake. Here's a quick photo roundup. 

Back in Chile

A year on from our last field season, and we’re back in Chile continuing our search for evidence of earthquakes and tsunamis. So far we’ve visited two new sites – Pucatrihue (west of Osorno) and Llico (3 hours further south). We are working on the salt marshes at these sites and are interested in the sequence of sediments which have accumulated in the marshes over time. As the environment (or elevation of the land relative to the sea) changes, the nature of the sediment which is deposited changes. We’re particularly interested in where we find a very sudden or sharp change in sediments; where we see the

Our new paper on Chilean earthquakes

Our first paper on Chilean earthquakes is now available online in the journal Quaternary Science Reviews. The paper is open access, so the full text is free for anyone to read.

The work we present sets out how we can use diatoms, microscopic algae, to quantify the changes in land level which occur during plate boundary earthquakes. We're interested in reconstructing these land level changes as they may provide a way of working out how big past earthquakes have been. Others have used similar approaches to identify and increase understanding of the threat posed by large earthquakes in Alaska, Japan and along the west coast of the United States. We apply the techniques to Chile, demonstrating that estimates of land level change using diatoms are accurate and useful.

Ed heads North

Ben, Daria and Isobel investigate the stratigraphy

Following Emma's departure back to the UK, I headed north from Valdivia for part 2 of my field season in Chile. Three buses, each slower and more decrepit than the last took me to Temuco, then Carahue and finally Tirua. Here, I met up with Marco Cisternas again, along with Lisa Ely, Alan Nelson, Rob Wesson and Isobel Hong from the US. Ben Horton and Daria Nikitina swelled our numbers to 8 when they arrived yesterday.

We've spent the last four days working at Quidico, a small river valley 20 minutes drive north of Tirua. We've been digging deep pits, cleaning river bank exposures and taking thin columns of sediment using a coring device to try to understand the sequence of sediments that has been laid down at the site. The presence of sand layers may suggest inundation by tsunamis.