I wish you well as you start your work in the private sector.

Nathalie and I as we are heading out from Seward to start our deployment.

Half of this work is the Community Near-trench Geodetic Experiment that is deploying 18 transponders across a large swath of the Aleutian trench 150° and 165°W. The instruments make up six geodetic sites that will be measured about once a year over the next four years to capture deformation associated with some of the largest earthquakes ever recorded. Our Apply-2-Sail students are writing a great blog as we progress.

The second half is a methodology experiment trying to push our deformation observations into deeper and steeper terrains. Here we are deploying a mesh geometry of transponders to test our capabilities to measure in water depths of up to 6000 m using a Wave Glider and lower frequency acoustics than for our other systems in the community sites. The mesh is also going in very steep seafloor (near the trench) where we will perform initial tests to determine repeatability with such differential water depths (and acoustic wave paths). Lastly, the Mesh, allows for lower cost observations in regions where we would like to obtain a dense field of deformation.

Scripps and Columbia crew working with the amazing folks running the Sikuliaq.

Follow more of our Seafloor Geodesy work here.

While not done here, such methods can be further strengthened by evaluating a suite of stations for the same periods to capture signals possible missed by some stations. Furthermore, though we classify only two types of impulse functions, the work strongly suggests we can apply such methods elsewhere for other seismic signals, including volcanic activity, landslides, and possibly slow-moving earthquakes.

Very exciting indeed!

Overall prediction accuracies from our generalized global neural network.

I was recently awarded funding for an exciting new technical experiment to push the limits of what we can do with GNSS-Acoustic-based seafloor geodetic observations. In the experiment, we are buying and deploying a new Wave Glider and 10 new transponders for deployment in the near-trench environment that are expected to be most responsible for large tsunamis.

Over three years we will specifically be testing (1) deep-water measurements using lower frequency transponders than commonly used, (2) observations that include high gradients of change across the seafloor, and (3) the application of a mesh-network design that can dramatically reduce the cost of observations where dense deformation data are helpful.

The deployment will occur in June/July 2024 on the RV Sikuliaq, during the initial deployment of instrumentation in Alaska for the Community Near-trench Geodetic Experiment. We will commence observations then, with a second Wave Glider deployment planned for 2025.

My co-investigators are Mark Zumberge at UCSD-Scripps, and Surui Xie at University of Houston. We will soon be looking for a postdoc to manage the data processing associated with this experiment.

A little more detail can be gained from the below image I pulled from the proposal.

The proposed experiment design.

The Thomas G. Thompson Research vessel is owned by the US Navy, managed by the University of Washington for the U.S. National Science Foundation, and docked at the NOAA and Oregon State site in Newport. Confusing, huh?

Plotting the course: Washington Scientist, John DeSanto explaining the route plan to the PIs (including me), and a varied group of early-career scientists ready to get their “sea legs”.

Seafloor Transponders: Well, not yet. These 7 transponders are going to be deployed offshore Washington and Oregon to complete the network of 6 new GNSS-Acoustic stations making of the Cascadia component of the Near-trench community experiment.

Pressure Drop: Not quite David Bowie-level, but one in three of each of the transponders being deployed have a pressure gauge within to measure the short-term changes in the height of the seafloor – possibly associated with very slow earthquakes.

Glider away!!! One of two autonomous surface vessels, called Wave Gliders, is over the ship and about to be let loose into the ocean for interrogating the transponders to determine their precise positions.

Robots at work: Wood’s Hole’s JASON Remotely Operated Vehicle (ROV) is going down to the seafloor to collect data from a different type of seafloor deformation sensor as a part of another project.

Before heading out to the field, we met individually with personnel from the Rwandan Mining Board (RMB), the Rwandan Environmental Management Agency (REMA), and the East African Institute for Fundamental Research (EAIFR).

We serviced our 7 continuous GNSS station, established one new campaign GNSS station, and performed a Magnetotelluric survey (MT), last part led by colleague Samer Naif. More of our project can be read here.

Scouting site for Magnetotelluric measurements along the Rwanda-DRC border looking toward Nyriagongo Volcano. GT Grad Student Derrick Murekezi, and RMB Employee Gaspard Nywandi with campaign GNSS station NNPN.