Please use this identifier to cite or link to this item: http://hdl.handle.net/2122/10577
AuthorsAlbano, Matteo* 
Barba, Salvatore* 
Solaro, Giuseppe* 
Pepe, Antonio* 
Bignami, Christian* 
Moro, Marco* 
Saroli, Michele* 
Stramondo, Salvatore* 
TitleAftershocks, groundwater changes and postseismic ground displacements related to pore pressure gradients: Insights from the 2012 Emilia-Romagna earthquake
Issue Date13-Jun-2017
DOI10.1002/2017JB014009
URIhttp://hdl.handle.net/2122/10577
Keywordsearthquake
InSAR ground deformation
Poroelastic rebound
afterslip
Coulomb stress
aftershocks
Subject Classification04.07. Tectonophysics 
AbstractDuring the 2012 Emilia-Romagna (Italy) seismic sequence, several time-dependent phenomena occurred, such as changes in the groundwater regime and chemistry, liquefaction, and postseismic ground displacements. Because time-dependent phenomena require time-dependent physical mechanisms, we interpreted such events as the result of the poroelastic response of the crust after the mainshock. In our study, we performed a two-dimensional poroelastic numerical analysis calibrated with Cosmo-SkyMed interferometric data and measured piezometric levels in water wells. The simulation results are consistent with the observed postseismic ground displacement and water level changes. The simulations show that crustal volumetric changes induced by poroelastic relaxation and the afterslip along the mainshock fault are both required to reproduce the amplitude (approximately 4 cm) and temporal evolution of the observed postseismic uplift. Poroelastic relaxation also affects the aftershock distribution. In fact, the aftershocks are correlated with the postseismic Coulomb stress evolution. In particular, a considerably higher fraction of aftershocks occurs when the evolving poroelastic Coulomb stress is positive. These findings highlight the need to perform calculations that adequately consider the time-dependent poroelastic effect when modeling postseismic scenarios, especially for forecasting the temporal and spatial evolution of stresses after a large earthquake. Failing to do so results in an overestimation of the afterslip and an inaccurate definition of stress and strain in the postseismic phase.
Appears in Collections:Papers Published / Papers in press

Files in This Item:
File Description SizeFormat 
JGRB52152.pdf3.89 MBAdobe PDFView/Open
Show full item record

Page view(s)

32
Last Week
8
Last month
checked on Jul 25, 2017

Download(s)

29
checked on Jul 25, 2017

Google ScholarTM

Check

Altmetric