Lower-crustal rheology and thermal gradient in the Taiwan orogenic belt illuminated by the 1999 Chi-Chi earthquake

Chi Hsien Tang, Ya Ju Hsu, Sylvain Barbot, James D.P. Moore, Wu Lung Chang

Research output: Contribution to journalArticlepeer-review

19 Scopus citations

Abstract

The strength of the lithosphere controls tectonic evolution and seismic cycles, but how rocks deform under stress in their natural settings is usually unclear. We constrain the rheological properties beneath the Taiwan orogenic belt using the stress perturbation following the 1999 Chi-Chi earthquake and fourteen-year postseismic geodetic observations. The evolution of stress and strain rate in the lower crust is best explained by a power-law Burgers rheology with rapid increases in effective viscosities from ~1017 to ~1019 Pa s within a year. The short-term modulation of the lower-crustal strength during the seismic cycle may alter the energy budget of mountain building. Incorporating the laboratory data and associated uncertainties, inferred thermal gradients suggest an eastward increase from 19.5±2.5°C/km in the Coastal Plain to 32±3°C/km in the Central Range. Geodetic observations may bridge the gap between laboratory and lithospheric scales to investigate crustal rheology and tectonic evolution.

Original languageEnglish
Article numbereaav3287
JournalScience Advances
Volume5
Issue number2
DOIs
StatePublished - 27 Feb 2019

Fingerprint

Dive into the research topics of 'Lower-crustal rheology and thermal gradient in the Taiwan orogenic belt illuminated by the 1999 Chi-Chi earthquake'. Together they form a unique fingerprint.

Cite this