Current Research
Deploying ocean bottom seismographs at dawn on the Mid-Cayman Rise from R/V Marcus Langseth, December 2022.
|
Detachment Faulting and Seismicity on Mid-Ocean Ridges
A large proportion of the oceanic lithosphere is probably formed by slip on long-lived, low angle faults called detachments. These detachments roll over to form corrugated domes, called oceanic core complexes, where deep-seated rocks are exposed on the seafloor. Although we can map detachment faults on the seabed, their subsurface geometry remains unclear. For example, we don't fully understand how detachment faults roll over to low angles, how they initiate, or how they cease to slip. Starting December 2022, we will be monitoring microearthquakes on the Mount Dent detachment fault system, on the Mid-Cayman Rise with a network of 40 ocean bottom seismographs. |
Controls of submarine Alvin during mission AL5003 to the seafloor at the East Pacific Rise, depth ~3200 m
|
Submarine Volcanism
at 9°N, East Pacific Rise We are studying the processes of volcanism, heat flow and hydrothermal circulation at the fast-spreading East Pacific Rise. Using data collected by Autonomous Underwater Vehicle Sentry and the submersibles Jason and Alvin, we are quantifying the driving forces behind repeated eruptions at 9°50'N, where we have collected data in 2018, 2019, 2021 and 2023. We will be monitoring the build up to a future eruption during National Science Foundation sponsored expeditions to the 9°50'N area, the next of which is planned for spring 2024. |
RV JOIDES Resolution in San Diego for port call, fall 2019
International Ocean Discovery Program
Expedition 395
Mantle Convection, Paleoceanography and Climate Evolution in the North Atlantic Ocean
We plan to test hypotheses about the origins of the V-shaped ridges, and how the Iceland plume has influenced oceanic circulation, by drilling V-shaped ridges and troughs off-axis and the fine-grained sediments that lie above. Check out the Scientific Prospectus for more details.
Expedition 395C was completed in summer 2021, and Expedition 395 is scheduled on the JOIDES Resolution for summer 2023. More details here.
Thermal pulses cause V-shaped anomalies in oceanic crust
Dynamics of the Iceland
Mantle Plume
In the North Atlantic Ocean, the Iceland plume is bisected by the Reykjanes Ridge ridge, which acts as a tape-recorder of the temporal variability of the plume. This transient behavior can be observed by the pattern of V-shaped features either side of the Reykjanes Ridge. We have used seismic reflection profiles to image the V-shaped ridges and construct a complete record of transient periodicity that can be traced back ~55 million years. This continuous record of convective activity suggests that the otherwise uniform thermal subsidence of sedimentary basins, which fringe the North Atlantic Ocean, has been punctuated by periods of variable dynamic topography.
Mantle Plume
In the North Atlantic Ocean, the Iceland plume is bisected by the Reykjanes Ridge ridge, which acts as a tape-recorder of the temporal variability of the plume. This transient behavior can be observed by the pattern of V-shaped features either side of the Reykjanes Ridge. We have used seismic reflection profiles to image the V-shaped ridges and construct a complete record of transient periodicity that can be traced back ~55 million years. This continuous record of convective activity suggests that the otherwise uniform thermal subsidence of sedimentary basins, which fringe the North Atlantic Ocean, has been punctuated by periods of variable dynamic topography.
