← Back to Sessions

WITHDRAWN Characterization of Shallow Seismic Sources in the Neuquén Province, Argentina

Description: 

WITHDRAWN The Neuquén province in southwest Argentina is a major center of oil exploitation. Since 2014, several companies started hydraulic fracturing to enhance oil production in one of the biggest unconventional shale gas-oil reservoir in the world: the Vacamuerta reservoir. This reservoir covers a region of ~30,000 km² and is mainly located in the Neuquén province at 2.5-3.5 km depth. Previously, the province was characterized by low seismic hazard (seismic zones 1 and 2 since the official Seismic Zonation Map of Argentina), with a PGA of 0.04 g and 0.1 g, respectively for a return period of 475 years.

Since 2015, the population of Neuquén has reported unusual seismic activity, mainly close to Sauzal Bonito and Añelo. During January of 2019, more than 20 felt seismic events were reported and a rare Mw 4.9 earthquake occurred two months later. This seismic activity generated a strong social concern about the relative increase in seismicity within the Neuquén province and its possible relation to the anthropic activity. By the end of June of 2019, the National Institute of Seismic Prevention (INPRES) of Argentina and the Seismology Laboratory of the Geosphere and Biosphere Research Center (CIGEOBIO dependent on the National University of San Juan and the National Council for Scientific and Technical Research), installed 2 broad-band seismic stations in the Sauzal Bonito and Añelo localities. We will present results from analyzing the respective seismicity which included more than 100 earthquakes with M_L magnitudes from 0.6 up to 3.8 between 2019 and 2020. Due to the sparse network, we located events using a single-station multicomponent algorithm, after applying a time correction for a strong anisotropy effect on the horizontal components. We combine cross-correlation analysis and composite focal mechanism solutions, and resolve more than 4 undocumented active seismic sources near Sauzal Bonito and Añelo. Safe and sustainable oil field operations in Neuquén likely require improved long-term monitoring and seismic hazard mitigation.

Session: Mechanistic Insights into Fluid-induced Earthquakes from the Laboratory to the Field [Poster]

Type: Poster

Date: 4/15/2025

Presentation Time: 08:00 AM (local time)

Presenting Author: Gerardo

Student Presenter: No

Invited Presentation: 

Poster Number: 102

Authors