Diagram showing how groundwater disappears into crustal ruptures formed during an earthquake
There are many mechanisms that can explain a sudden water level drop after an earthquake. The unique dataset in this paper shows that the most likely cause of water disappearing is that it flows into crustal ruptures that are newly formed during the earthquake. Credit: Hosono et al. [2019], Figure 6
Source: Water Resources Research

Major earthquakes are known to affect surface water and groundwater systems; for instance, by altering spring locations, making streams disappear, or causing groundwater levels to drop temporarily or permanently. The study by Hosono et al. [2019] is unique because it provides a rare set of high frequency observations of groundwater and surface water levels before, during, and after a large earthquake.

These data reveal that a large volume of water has disappeared through crustal ruptures formed during the quake, as shown in the diagram above. Not only does this reduce water availability in the region for a whole year but it also causes surface water and shallow groundwater to mix with deeper groundwater with possible long-term negative consequences for groundwater quality.

Citation: Hosono, T., Yamada, C., Shibata, T., Tawara, Y., Wang, C.‐Y., Manga, M., et al. [2019]. Coseismic groundwater drawdown along crustal ruptures during the 2016 Mw 7.0 Kumamoto earthquake. Water Resources Research, 55. https://doi.org/10.1029/2019WR024871

—Marc F. P. Bierkens, Editor, Water Resources Research

Text © 2019. The authors. CC BY-NC-ND 3.0
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