Mechanical Response of Shallow Crust to Groundwater Storage Variations: Inferences From Deformation and Seismic Observations in the Eastern Southern Alps, Italy
Abstract
Changes in continental water storage generate vertical surface deformation, induce crustal stress perturbations, and modulate seismicity rates. However, the degree to which regional changes in terrestrial water content influence crustal stresses and the occurrence of earthquakes remains an open problem. We show how changes in groundwater storage, computed for a ∼1,000 km² basin, focus deformation in a narrow zone, causing large horizontal, nonseasonal displacements. We present results from a karstic mountain range located at the edge of the Adria‐Eurasia plate boundary system in Northern Italy, where shortening is accommodated across an active fold‐and‐thrust belt. The presence of geological structures with high permeabilities and of deeply rooted hydrologically active fractures focus groundwater fluxes and pressure changes, generating transient surface horizontal displacements up to 5 mm and perturbations of crustal stress up to 25 kPa at seismogenic depths. The background seismicity rates appear correlated, without evident temporal delay, with groundwater storage changes in the hydrological basin. With no evidence of pore pressure propagation from the hydrologically active fractures, seismicity modulation is likely affected by direct stress changes on faults planes.
Additional Information
© 2021 American Geophysical Union. Issue Online: 16 February 2021; Version of Record online: 16 February 2021; Accepted manuscript online: 25 January 2021; Manuscript accepted: 20 January 2021; Manuscript revised: 15 January 2021; Manuscript received: 13 July 2020. We thank L. Anderlini for helpful discussions and suggestions on stress analysis and E. Scoccimarro for suggestions on the analysis of pluviometric data. This work and F. Pintori are supported by the project TRANSIENTI, founded by the Italian Ministry of Education, Universities and Research (MIUR) "Premiale 2014." L. Longuevergne acknowledges the support of SNO H+ and OZCAR Research Infrastructure. Data Availability Statement: Precipitation, temperature, and river flow data are provided by "Agenzia Regionale per la Prevenzione e Protezione Ambientale del Veneto" (ARPAV): https://www.arpa.veneto.it/bollettini/storico/Mappa_2019_TEMP.htm. Extraterrestrial irradiance data are available from http://www.soda-pro.com/web-services/radiation/extraterrestrial-irradiance-and-toa. Drainage direction maps used to define river basins are available on www.hydrosheds.org/page/availability. The analyzed seismic catalog is available in the supplementary material of Romano et al. (2019). We use publicly available raw GNSS data. However, RINEX data can be requested from authors, if not yet available on the original repositories. Raw GPS time series are available on https://doi.org/10.1594/PANGAEA.912895. The Collalto Seismic Network data are available on https://doi.org/10.7914/SN/EV. GRACE EWT data: D. N. Wiese, D.‐N. Yuan, C. Boening, F. W. Landerer, M. M. Watkins. 2019. JPL GRACE and GRACE‐FO Mascon Ocean, Ice, and Hydrology Equivalent Water Height JPL Release 06 Version 02. Ver. 2. PO.DAAC, CA, USA. Data set accessed [2020‐04‐29] at https://doi.org/10.5067/TEMSC-3MJ62. The MATLAB code for GWS estimation is available from http://dx.doi.org/10.17632/m5p5xmrr7k.1. The MATLAB code for vbICA decomposition is available from http://dx.doi.org/10.17632/n92vwbg8zt.1.Attached Files
Published - 2020JB020586.pdf
Supplemental Material - 2020jb020586-sup-0001-movie_si-s01.mp4
Supplemental Material - 2020jb020586-sup-0002-supporting_information_si-s01.docx
Files
Name | Size | Download all |
---|---|---|
md5:0dadbfcdd9bf462c9105b7ebdf202a13
|
13.0 MB | Preview Download |
md5:17931177688fa359819f9d2152eb9ec8
|
6.7 MB | Download |
md5:2c8e18281c002ce99f3cbfe892992ed1
|
10.3 MB | Download |
Additional details
- Eprint ID
- 107728
- Resolver ID
- CaltechAUTHORS:20210126-125516766
- Premiale 2014
- Ministero dell'Istruzione, dell'Universita e della Ricerca (MIUR)
- University of Rennes
- Created
-
2021-01-26Created from EPrint's datestamp field
- Updated
-
2023-06-01Created from EPrint's last_modified field