This cruise represents a collaborative effort between scientists from the University of Texas at Austin, Oregon State University and the Universidad de Chile. We are currently on board the R/V Marcus Langseth, a US research ship supported by the National Science Foundation and the operated by the Lamont-Doherty Earth Observatory.

Our goal is to image the structure of the continental margin along a 1400-km long segment offshore south-central Chile that includes the source region of the 2015 Illapel , 2010 Maule and 1960 Valdivia earthquakes to better understand the characteristics of the plate boundary that allow subduction zone slip events to grow into giant subduction zone events. All earthquakes begin small; a great earthquake occurs when the plate boundary remains locked long enough to accumulate enough strain in the adjacent plates to lead to a large amount of slip and when that slip can propagate over a large area without encountering barriers. Our overarching objective is to identify features of Earth structure that can be compared to other geophysical observations made before, during and after large earthquakes in order to better understand the physical processes that lead up to a great earthquake. This knowledge should result in more accurate and detailed models for interpreting ongoing observations in an effort to better anticipate great earthquakes in the Chile subduction zone and elsewhere.

On January 9, prior to leaving port, we hosted tours of the ship for distinguished visitors, including President Michelle Bachelet of Chile, the President of the Chilean Science Foundation and the US Ambassador to Chile. The ship’s crew and the scientific and technical leaders of the CEVICHE science party discussed the objectives of the cruise as well as highlighting the tools to be used for this project. For a discussion of cruise objectives in Spanish, see http://impresa.lasegunda.com/2017/01/13/V/fullpage#slider-8. After refueling while at anchor off Valparaiso, we got underway on the evening of January 11.

We invite you to return to this blog as we add posts about life at sea, who we are, what we are learning.