Marine expedition to image the earth below Aleutian volcanoes
In September-October 2020, a group of scientists from Woods Hole Oceanographic Institution and Northern Arizona University are collecting marine seismic data to image Earth structure below Aleutian volcanoes aboard the R/V Marcus G. Langseth. We’re blogging about the science, life at sea, and more….
It’s a wrap
Yesterday morning, we finished acquiring data on our final profile and recovered all of the seismic gear, with beautiful morning views of Aleutian volcanoes, especially Great Sitkin. We have collected a really exciting dataset, and I can’t wait to start analyzing the data in more detail and finding out what they’ll teach us about the…
Picking up strange signals
We carefully monitor all of the data that we are collecting from the main lab, located in the bowels of the ship, below the water line. This is mission control for the scientific operations. A bank of 46 screens (!) display every conceivable kind of information about data that we are collecting, including the position…
A typical day on the R/V Langseth
The talented Valeria Cortes Rivas (U. Chile / Northern Arizona University) illustrated a day in her life on R/V Langseth as a graduate student. Go back to Aleutians Field Blog
Data streaming in…
During the second phase of our cruise, we are collecting seismic imaging data using a long cable (6 to 9 km) filled with pressure sensors that we tow behind the ship, traveling very slowly. The streamer records sound waves emitted by our seismic source that have bounced off of layers in the Earth. The close…
Weather is king
Weather rules supreme in maritime operations. All plans are shaped around the forecast. For the last week, we have been carefully monitoring forecasts that predicted a large storm would sweep through our field area on Sunday and Monday (Sept 20-21), bringing >45 mph winds and >20 ft seas. In response, we decided to cut some…
Out of the water and back in again
Over a four day period, we picked up nearly all of the ocean-bottom seismometers from our first transect along the Aleutian volcano chain between Seguam and Gareloi Islands and put them back out again on a transect across the chain near Atka. To summon the ocean bottom seismometers back from the seafloor, we steam to…
Me vs. Ship
My main exercise on the ship is running on the treadmill, when it’s calm enough. During a run the other day, it occurred to me that my pace on a treadmill at sea (with the ship motion) was similar to the speed that the R/V Langseth steams when we are towing gear and acquiring data…
Singing to the seismometers
During this cruise, we are using sound waves to image geological structures deep below the seafloor. Determining the structure of Earth’s interior is one of the main types of seismology, and seismologists use a wide range of techniques and types of seismic waves to examine different depth intervals and resolutions. Many of these approaches use…
Deploying ocean bottom seismometers around the spectacular Aleutian Islands
Now that we have finally arrived in our field area, we have spent the last two days steaming along a ~300-mile-long stretch of the Aleutian island chain between Seguam and Gareloi islands and deploying ocean bottom seismometers (OBS) from Woods Hole Oceanographic Institution and Scripps Institution of Oceanography on our first transect (see this post…
The long trip west (and a little science on the way)
To travel from Ketchikan, Alaska to our field area in the western Aleutians requires us to steam 1700 miles – nearly the entire width of Alaska (and Alaska is big). By any mode of transportation, this is a long trip, but especially by ship. Research ships generally go a maximum speed of 10-11 knots (11.5-12.5…
Whale watching from the treadmill
Most research vessels have small gyms where people onboard can get a little exercise while at sea. A nice thing about the gym on the R/V Langseth is that it is well above the water line and has some windows, so you can look out at the sea while you log some miles on the…
What are we doing out here?
The Aleutian arc is an active string of volcanoes formed over a subduction zone, where two of Earth’s tectonic plates collide and one is forced under the other. These geological settings create the largest and most destructive earthquakes and tsunamis and some of the most active volcanoes on the planet. While some of the magma…
Quarantine in Ketchikan…
A part of the marine science gig has always been spending weeks or even months away from home in isolated environments, but COVID-19 has added a new twist. To ensure that no one boarding the ship has the coronavirus, each of us had to quarantine at least 2 weeks in a hotel room in port…
