Research

Investigating the Mechanics of Strain Partitioning at the Rakhine-Bangladesh Megathrust Using InSAR Time-series

Advised by Eric Lindsey

Collaborators: Bar Oryan, Lin Shen, Michael Steckler

The Rakhine-Bangladesh megathrust is overlaid by km-deep sediments allowing us to characterize the shallow properties of the megathrust on land. Here, we processed the ALOS-2 InSAR time-series and identified regional scale structures that could affect the seismic potential in the region.

This research is funded by NASA FINESST 2022.

Published Paper

Chong, J.‐H., Oryan, B., Shen, L., Steckler,M. S., & Lindsey, E. O. (2025).Interseismic uplift of anticlines above the Rakhine‐Bangladesh megathrust from ALOS‐2 InSAR. Journal of Geophysical Research: Solid Earth, 130,e2024JB030003. https://doi.org/10.1029/2024JB030003 

Improving megathrust coupling using realistic parameters

Advised by Eric Lindsey

This research is funded by NASA FINESST 2022.

In prep

Modeling deformation of the Cascadia Subduction Zone

Advised by Eric Lindsey

The dense GNSS network in the Pacific Northwest provides a unique opportunity to study the late interseismic phase of subduction since the 1700 earthquake. The GNSS observations show a broad regional subsidence along the Cascade volcanic arc even after correcting for non-tectonic processes, including hydrology and glacial isostatic adjustment. We construct a viscoelastic model of the subduction to understand the source of this broad subsidence better and examine the influence of geometry, plate thickness, deep slip on the megathrust, and a potential low-viscosity mantle wedge. Preliminary tests show that plate geometry has a greater influence on the surface displacement as compared to mantle viscosity. 

This research is funded by NASA FINESST 2022.

In prep

Evaluating Strain Partitioning in the Pacific Northwest using block modeling

Advised by Eileen L. Evans

The Cascadia subduction zone is an oblique subduction zone capable of producing megathrust earthquakes (e.g., the 1700 Cascadia earthquake). This study aims to better understand how oblique Juan de Fuca-North America convergence is partitioned between surface faults in the Pacific Northwest region and the subduction zone using block models. 

In revision

Presentations

SSA 2021 presentation - (link)

Sub-Pixel Offset analysis of the 2018 Mw 7.5 Papua New Guinea Earthquake

Advised by Mong-Han Huang

The 2018 Mw7.5 earthquake was the largest earthquake recorded in the Papua New Guinea Highlands. We were able to resolve near-field deformation using the sub-pixel offset of Sentinel-1 SAR images. Our results show up to 2 meters of uplift and 4 meters of horizontal displacement as well as triggered landslides. We propose that the earthquake ruptured two separate faults of different geometries and it is possible that it involved a detachment fault.

This is a continuation of my undergraduate research on the same topic advised by Mong-Han Huang. 

Published paper

Chong, J.-H., and M.-H. Huang (2020). Refining the 2018 Mw 7.5 Papua New Guinea Earthquake Fault-Slip Model Using Subpixel Offset, Bull. Seismol. Soc. Am. 111(2), 1032–1042, doi: 10.1785/0120200250

Seasonal influence on post-fire debris flow likelihood after the 2020 Lake Fire

Advised by: Scott Hauswirth, Louis Scuderi, Eric Lindsey

Collaborators: Adit Ghosh, Brandon Page, Gregory Jesmok, Denise V. Berg, Marlene Lopez, Deepshika Upadhyay, David Stone, 

We show in this research a post-fire debris flow analysis for the 2020 Lake Fire in Southern California, USA, over the span of four years. Specifically, we used high-resolution satellite imagery and field surveys (during the first and fourth years) to inform our simulations. Post-fire debris flow likelihood is still elevated in the fourth year, but can vary depending on the season. We found that hydraulic conductivity exerts the greatest control for debris flow initiation, whereby drier months significantly increase the hydraulic conductivity, reducing the likelihood of debris flows. This finding adds to the already very little literature on the influence of seasonality in the long-term analysis of post-fire debris flows.

I'm also interested in applying this method to fires affected by monsoons (e.g., Hermits Peak/Calf Canyon in New Mexico).

In review

Estimating river properties using DEM

Collaborators: Adit Ghosh and Scott Hauswirth

This project started as a hydrogeology class project inspired by the question "How can we estimate the river sediment discharge of a river with limited access for sample collection?". In this study, we propose a method to estimate the river properties along a river (water stage, velocity, discharge, sediment discharge, etc) with limited gauging stations by using only freely available Digital Elevation Models (DEM) and software. 

Presentations

• AEG 2020 poster presentation of this project (click here) & poster only (click here)