Wednesday, 2 April 2014
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
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
Thursday, 6 February 2014
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
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.
Tuesday, 14 January 2014
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.
Sunday, 12 January 2014
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