Title: Imaging Trans-Crustal Magmatic Systems with Receiver Functions: A Path Towards Linking Tectonic and Eruptive Processes
Abstract: Understanding the connection between the transport of magma from the mantle to shallow emplacement and eruption processes requires knowledge of magma storage depths throughout the crust. Despite this, constraints from the mid-crust to upper mantle are typically limited to volcanoes that fortuitously have properties that illuminate the deep system (e.g., deep volcanic seismicity, preserved petrologic evidence of deep crustal storage, etc.), or those where high-resolution geophysical experiments have taken place. Here, I demonstrate the utility of the seismic receiver function technique for providing new insights related to magma storage in the crust using two case studies. The first focuses on providing systematic depth estimates of crustal magma storage at all sufficiently monitored (> 3 broadband seismometers) volcanoes in the Aleutian arc. A significant barrier for understanding arc magmatism is the need to constrain whole-crustal magmatic architecture at a significant number of arc volcanoes such that we can sufficiently sample different subduction parameters. Here, we leverage receiver functions to provide first-order constraints at arc volcanoes with minimal requirements for seismic station distribution. The second case study focuses on a seismic nodal deployment on the Southwest Rift Zone of Kīlauea. Here, recent increases in deep seismicity, called the Pāhala seismic swarm, have been interpreted as an increase in mantle magma flux, with potential lateral transport pathways towards the central edifices of either Kīlauea or Mauna Loa. We aim to use receiver functions in conjuction with local seismic tomography to provide high resolution images extending to swarm depths to provide independent constraints on mantle magmatic structure.
Biography: Dr. Helen Janiszewski is a seismologist and an Assistant Professor in the Department of Earth Sciences in the School of Ocean and Earth Science and Technology (SOEST) at University of Hawaiʻi at Mānoa in the Geophysics and Tectonics research division. Her research is focused on using seismic data to image the structure of the Earth’s crust and mantle, particularly at subduction zones and volcanoes. She uses a variety of seismic imaging techniques, and is currently focused on understanding relationships between structure and earthquake behavior at subduction zones, and constraining magmatic systems and transport beneath volcanoes. She is also involved in technique improvement and development for seismic data collected from ocean bottom seismometers, with particular application to broadband amphibious (onshore/offshore) deployments. Her research currently includes geographic focus sites at the Cascadia, Alaska/Aleutian, and Vanuatu subduction zones, as well as Hawaiian volcanoes.
To join virtually: Zoom
Contact: hajanisz@hawaii.edu
Website: https://helenjaniszewski.squarespace.com/helenjaniszewski
Recording: Zoom Recording (will be available within a week after the seminar)