DOI: 10.5061/dryad.1ns1rn923
title: Interseismic uplift of anticlines above the Rakhine-Bangladesh Megathrust from ALOS-2 InSAR

description: The shallow portion of a megathrust represents the zone of first contact
 between two colliding plates, and its rheological properties control the
 seismic and tsunami hazards generated by the fault. Unfortunately,
 underwater geodetic observations are sparse due to the high cost of
 obtaining geodetic data, meaning limited information is available on the
 interseismic behavior of this part of most megathrusts. The
 Rakhine-Bangladesh megathrust offers a unique opportunity to probe the
 behavior of the shallow megathrust as it is the only ocean-continent
 subduction zone where the near-trench region is fully accessible on land.
 Here, we use observations from ALOS-2 wide-swath imagery spanning 2015 to
 2022 to conduct an InSAR timeseries analysis of the overriding plate
 within Bangladesh and the Indo-Myanmar Ranges. We identify a narrow
 pattern of alternating uplift and subsidence associated with mapped
 anticlines but show that it cannot be explained by plausible rates of slip
 on the megathrust or other fault structures. Instead, we argue that the
 deformation is likely caused by active aseismic folding within the wedge
 above a shallow decollement. We show that estimates of the decollement
 depth derived from a viscous folding model and the observed anticline
 spacing are in agreement with previous seismic observations of the
 decollement depth across the fold belt. We suggest that the role of
 ductile deformation in the overriding plate in subduction zones may be
 more important than previously recognized.
description: # Interseismic uplift of anticlines above the Rakhine-Bangladesh
 Megathrust from ALOS-2 InSAR 
 [https://doi.org/10.5061/dryad.1ns1rn923](https://doi.org/10.5061/dryad.1ns1rn923) This file contains the dataset and MATLAB scripts of the manuscript for processing and analysis for Chong et. al., (2024), Interseismic uplift of anticlines above the Rakhine-Bangladesh Megathrust from ALOS-2 InSAR in *JGR: Solid Earth.* ## Description of the data and file structure ##### Final\_fitted\_InSAR\_velocity\_masked.tif * GeoTiff version of the final Line-of-Sight (LOS) velocities as shown in Figure 2 of the main paper * LOS units are in meters/year ##### Textfiles folder * This folder contains the Line-of-Sight (LOS) velocities and DEM in a textfile format for all the 3 selected cross-section transects: * "_full.txt" indicates the original textfile without downsampling * Central-Anticlines transect * Chittagong transect * Northern transect * Textfiles of the **starting** parameters for the Bayesian Monte Carlo estimation for each of the dislocation models * Textfiles of the **optimized** parameters for the Bayesian Monte Carlo estimation for each of the dislocation models * Textfiles will consist of "_Optimized.txt" * Header lines for the starting and optimized parameter textfiles are in the format below: * Lon (°), Lat (°), Depth (km), Strike (°), Dip (°), Length (km), Width (km), Rake (°), Slip (cm/yr), Open (cm/yr), Notes * Rake angles of the fault describes 0 = left-lateral; -90 = normal; 180 = right-lateral; 90 = reverse; ##### Scripts folder * All relevant MATLAB scripts and the functions used to estimate the Bayesian Monte Carlo estimation for the dislocation models ##### GNSS\_ITRF14\_ref * All GNSS stations with time-series textfiles that were converted from ITRF14 reference frame; include the velocities named "all_gnss_vel.txt". * Format are in year; east velocities; north velocities; vertical velocities; units are described in textfile header ##### GNSS\_Indian\_ref * All GNSS stations with time-series textfiles that have been converted from ITRF14 to the Indian reference frame; include the velocities named "all_gnss_vel_converted.txt". * Format are in year; east velocities; north velocities; vertical velocities; units are described in textfile header