geodesy – Geobites

February 18, 2021February 17, 2021

Cracking the code of the caramel crust

Featured image: a view of the Calico Basin in the eastern part of the Mojave Desert. Photo by Fred Morledge, CC BY-SA 2.5, via Wikimedia Commons.

Paper: Thin crème brûlée rheological structure for the Eastern California Shear Zone
Authors: Shaozhuo Liu, Zheng-Kang Shen, Roland Bürgmann, & Sigurjón Jónsson

A recent paper by Liu and colleagues aims to answer a fundamental question in geodynamics: are Earth’s tectonic plates more like a jelly sandwich, or a crème brûlée? It may sound silly, but these two models for crustal strength describe how tectonic plates might respond to stress changes due to earthquakes.

July 9, 2020July 9, 2020

Tiny wobbles foreshadow big earthquakes

Featured image: A GPS station in the Sawtooth National Forest near Ketchum, Idaho. Photo by Scott Haefner (USGS).

Paper: Months-long thousand-kilometre-scale wobbling before great subduction earthquakes
Authors: J. R. Bedford, M. Moreno, Z. Deng, O. Oncken, B. Schurr, T. John, J. C. Báez, M. Bevis

We’re always on the lookout for earthquake precursors, indicators that the Earth might be gearing up for some shaking, and geophysicists think they might have found a new one: a small but measurable back-and-forth “wobble” of the land starting several months before very big earthquakes hit.