Research Themes

I am an observational seismologist who develops and applies passive-source seismic methods to interpret Earth structure and processes. My work focuses on intraplate ocean islands and the mantle upwellings that generate them. I am interested in how volatiles and crustal materials transported into the deep mantle via subduction are returned to the surface. A growing body of research highlights that these islands tap materials stored at a wide range of depths, but it is unclear how much recycled material is returned to the surface. Further, deep mantle upwellings have been shown to interact with and modify their overlying lithosphere in different ways. Constraining how mantle upwellings cycle volatiles and recycled crust through the solid Earth is important because both are key factors for climate stability and planetary habitability.

Ocean Islands

Intraplate volcanic ocean islands are a window into deep mantle processes. The traditional model for intraplate islands suggests they originate from hot mantle plumes that transfer material from the core-mantle-boundary to the overriding lithosphere (e.g., tectonic plate). However, not all intraplate ocean islands fit this model. Part of my research focuses on understanding how mantle upwellings modify the lithosphere and form ocean islands. I am interested in islands that do (e.g., Hawaiʻi) and don’t fit the mantle plume formation model (e.g., Bermuda). I use seismic methods to determine whether magmas that fail to erupt form an underplate and change lithospheric thickness. The presence, or lack of, an underplate is important for constraining plate buoyancy and strength as well plume dynamics. I am presently expanding into using microseismicity to characterize the state of stress within these environments, with a focus on Bermuda.

Mantle Transition Zone

The mantle transition zone (MTZ), located between about 400-700 km depth, is a key component of the solid-Earth system. Defined by a series of seismically-detectable mineral phase transitions, MTZ minerals can host much more water (H) than the rest of the mantle. Subducting slabs can transport H, C, and recycled crust to the MTZ, but whether and how such materials are transported back to the surface is uncertain. Recycled materials from the MTZ may source intraplate volcanic ocean islands that lack a mantle plume. I use seismic imaging constrain the chemical and thermal state of the MTZ globally and below ocean islands of interest. I place particular emphasis on the seismic detectability of interfaces within MTZ associated with recycled materials. My ultimate goal is to identify where and how recycled materials are transported from the MTZ to the surface.