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Meet a Geophysicist: Emilie Hooft

5 minutes

(Describer) Titles: Earthscope Chronicles. Volcano Research – Emilie Hooft.

I'm a geophysicist. So a geophysicist is someone who uses physics to understand geology, or the earth. And physics is particularly useful because it means we can access parts of the earth where a geologist can't get to look at rocks. I got into it by using physics to understand the earth underneath the oceans, so we can get to those parts of the earth. We also use physics to study deep inside the earth.

(Describer) A 3D computer model shows an underground formation.

I'm working on two kinds of projects right now. The first one is understanding the structure and magma plumbing beneath volcanoes, and I'm working both on land and in the oceans on that problem. On land, I'm working at Newberry Volcano, which is a big shield volcano, so it has a low profile, in Oregon. And it's quite a hot volcano, so it's interesting to people for that reason. The other volcanoes I work on are underwater in the oceans. And right now, we're working on a part of that system just off the Pacific Northwest coast. The ridge system there is called the Juan de Fuca Ridge, and we're looking at a particular segment called the Endeavour Segment. That volcano is interesting because it has five separate hydrothermal vents that have been studied for a very long time, and these host very unusual life-forms. We're interested in the magma system that brings the heat and the chemistry that drives those hydrothermal vent systems. They have tube worms and they also have-- The really interesting animals on those vents are the bacteria that do the microscopic reactions and that are actually metabolizing sulfur and not using photosynthesis to derive their energy.

(Describer) They’re connected by lines in a microscopic image.

The science questions I'm interested in answering are related to how volcanoes work. So how magmatic melt is formed in the mantle, how it moves up, how it organizes itself inside the crust to actually form a focal point, and how it then forms magma chambers that erupt to generate volcanoes on the surface. To answer the questions, I primarily use seismology, which is using how earthquake energy travels through the earth. And in regions where there's magma, the velocity of the seismic waves will be slower than in regions where the rocks are more solid. This is a tool that we can use to understand magma and other structures deep inside the earth. We collect seismic data by putting instruments that record ground motion in the field. When we worked on Newberry, we had instruments that we buried into the ground. It's covered with ash there, so they're easy to bury. And then we have recording packages and batteries that record the motion of the ground as sound energy, or seismic waves, travel through the earth. In the oceans, it's more difficult, and we actually put these same instruments down on the seafloor. We go out with a ship, we have these instruments that's a package, we throw it overboard, and it sinks to the seafloor, and it sits there autonomously recording data. We come back and send it a signal, and it listens for this specific signal-- it's like a little birdsong. When it hears that signal, it drops the anchor, and it has enough flotation that it floats up to the sea surface. Then we look for it and pull the instrument back on board and download the data. The work that we're doing is useful because it can be used to better understand how a volcano might behave. So if we understand something about the structure of magma inside a volcano, then if it becomes more active, if there are earthquakes, if it starts emitting gas, if it starts inflating, we have a better idea of where magma's located and what those signs might mean for the potential of an eruption, how big, how explosive that eruption could be.

(Describer) An eruption flares underwater. Funding to purchase and make this educational program accessible was provided by the U.S. Department of Education. Contact the Department of Education by telephone at 1-800-USA-LEARN, or online at www.ed.gov.

Funding to purchase and make this educational production accessible was provided by the U.S. Department of Education.

PH:1-800-USA-LEARN (V) or WEB: www.ed.gov.

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Geophysicist Emilie Hooft describes her work and the important role physics plays in understanding volcanoes. She also reveals how data helps create the images of magma structures beneath volcanoes. Part of the “EarthScope Chronicles” series.

Media Details

Runtime: 5 minutes

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