Apply-to-Sail on

An Open Access Seismic Investigation of Galápagos Plume-Ridge Interaction

 March 6-April 6 2023

 

 

We are now accepting applications from graduate students and early-career scientists in the geosciences from U.S. institutions to sail on a marine expedition to deploy an array of ocean-bottom seismometers on the seafloor northwest of the Galápagos Islands.

 

The Galápagos area was among the very first locals ever to be recognized as involving the interaction between a mid-ocean ridge and an off-ridge hotspot.  Geochemical studies have demonstrated that mantle material melting and giving rise to the Galápagos islands is also feeding magmatism along the Galápagos Spreading Center (GSC).  Near-surface geophysical studies have shown that the hotspot is creating anomalously thick igneous crust at the GSC. Seismic waves recorded by seismometers on the islands show evidence for a hot mantle plume that is rising beneath the islands and tilting northward towards the GSC.  Despite over four decades of geologic, geophysical, and geodynamic studies of this area, we still have little knowledge of the physical processes by which mantle plume-ridge interaction actually occurs. 

 

Our team of geophysicists at the Universities of Oregon (Emilie Hooft, Douglas Toomey), Rhode Island (Yang Shen) and Hawaiʻi (Garrett Ito), will be conducting an ambitious ocean bottom seismometer experiment to image the upper mantle between the Galápagos Islands and the Western Galápagos Spreading Center.  We aim to address three sets of scientific questions:

1) At what depths, in what geographic pattern, and by what mechanism is mantle plume material, including melt, transported northward to the Galápagos Spreading Center (GSC) and along the spreading center?

2) Do the scale and nature of heterogeneity indicate small-scale, sub-lithospheric convection (SSC)? If so, how does that influence the flow of the mantle plume?

3) What is the spatial distribution of melting and volatile release, as well as the associated heterogeneity in composition and rheology associated with plume-ridge interaction? 

The answers to these questions address long-standing gaps in knowledge of hotspots and related volcanic systems, as well as fundamental processes of convection in the oceanic upper mantle.

 

We invite graduate students and early-career scientists to “Apply-to-Sail” with us on a 29-day seagoing cruise to deploy 53 ocean bottom seismometers (marked by yellow squares in image above showing the schematic design of the instrument array) on the deep seafloor between the islands and the Western GSC.  The instruments will sit on the seafloor for ~15 months recording seismic waves from distant earthquakes. The aim of the Apply-to-Sail program is to provide early-career, professional experience in marine geophysics and to promote ocean bottom seismic research to the up-and-coming generations of geoscientists.  We also aim to enhance professional access to the geosciences by minorities and other underrepresented groups. 

 

The cruise will be onboard the R/V Marcus G. Langseth embarking in San Diego CA, USA 06 March 2023 (sailing on 08 March), and disembarking on Puerto Ayora, Galápagos Islands, Ecuador, 06 April 2023.  While onboard, participants will gain an authentic experience of being a marine seismologist on a seagoing expedition. They will be on duty “standing watch” on two 4-hour shifts each day, during which they will maintain scientific logs of bathymetry and potential field surveys and seismometer deployment operations. They may also be asked to assist the crew on deck in the actual deployment of the instruments. As members of the science crew, participants will join regularly scheduled science meetings and have ample opportunity to engage with scientists, engineers, and graduate students with expertise and/or interests in marine seismology. All travel, lodging, and meal expenses will be covered for the participates. The principal investigators on this cruise will be Professors Emilie Hooft and Yang Shen.

 

Qualified applicants are pursuing training and/or careers in geoscience either by attending graduate school or as a researcher or a pre-tenured professor in the U.S. To apply, please send (1) a brief cover letter,  (2) a one-page statement describing your background, professional ambitious and interests in participating, as well as (3) a curriculum vitae to Professor Garrett Ito at gito@hawaii.edu. Applications received by November 1, 2022 will receive highest priority for consideration.