New paper on seismicly measured vadose zone soil moisture dynamics

Vadose zone soil moisture—water stored in the unsaturated region between the surface and the groundwater table—is often considered a pivotal intermediary water reservoir in semi-arid regions. In face of climate variability, understanding its dynamics in response to changes in meteorologic forcing patterns is essential to enhance the resiliency of our ecological and agricultural system. However, the inability to observe vadose zone soil moisture at large spatiotemporal scales hinders quantitative characterization. Here, utilizing pre-existing fiber-optic cables as seismic sensors, we demonstrate a fiber seismic sensing principle to robustly capture vadose zone soil moisture dynamics. Our observations in Ridgecrest, California, reveal sub-seasonal precipitation replenishments and a prolonged drought in the vadose zone.

This work is a collaborative effort with Zhongwen Zhan group at Caltech, and is lead by Dr. Zhichao Shen and Dr. Yan Yang, with contributions from Dr. Kyra Adams (JPL) and Dr. Ettore Biondi. It all started with a coffee discussion at Red Door Cafe.

Read the paper here. See also news article by Caltech news.