Seismic expression of active extensional faults in northern Umbria (Central Italy)

Collettini, Cristiano; Barchi, Massimiliano R.; Pauselli, Cristina; Federico, C.; Pialli, G.

doi:10.1016/s0264-3707(99)00059-9

Cited by 35 publications

(18 citation statements)

References 5 publications

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“…All the other events in the surrounding clusters occurred outside this frame of reference. The selected events (red dots) represent hypocentres on the Martana fault, a normal fault zone in the direction of strike NNW–SSE, as typically found in Umbria (Collettini et al. 2000; Bonini et al.…”

Section: Discussionmentioning

confidence: 99%

Geodynamically induced variations in the emission of CO₂gas at San Faustino (Central Apennines, Italy)

2011

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The Central Apennines are affected by frequent earthquakes of moderate magnitude that occur mainly within the upper part of the crust at depths of <15 km. A large number of cold gas emissions that are rich in CO2 are also found in the region. One particular vent with a high rate of degassing was equipped with a sensor to measure flow rates, which were recorded for a number of different periods between 2005 and 2010. Factors that could affect potentially CO2 flow rates include barometric pressure, atmospheric temperature, precipitation and local seismicity. Our analysis indicates that the periods of anomalous flow rate were related not to the environmental factors but probably to the deformative processes of the crust associated with the local seismicity. Local seismic events as expression of geodynamic processes occurred always before and during these anomalous gas flow periods. This correlation exists only for events that occurred eastwards of the gas emission site close to the Martana fault zone. We herein consider this correlation as indication for a continuous interaction between the field of static strain and the deep fluid pressure. An approximation of the fluid pressure transmission towards the gas emission site gives reasonable values of 1–10 m2 sec−1. To make comparisons with the long‐term effects of the static strain, we also recorded the short‐term effects of the dynamic release of strain induced by the series of strong earthquakes that took place in L’Aquila in 2009. We detected a significant anomalous flow rate that occurred at the same time as this seismic sequence, during which widespread degassing was induced around the focal zone.

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Section: Discussionmentioning

confidence: 99%

Geodynamically induced variations in the emission of CO₂gas at San Faustino (Central Apennines, Italy)

2011

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“…The Umbria region, is characterized by Pliocene active extensional tectonics [ Collettini et al , 2000]. These tectonics generated continental basins with a general NNW‐SSE trend, bordered either by WSW‐dipping or ENE‐dipping normal faults striking in the same direction [ Bally et al , 1986; Barchi et al , 1998a].…”

Section: Geology and Tectonicsmentioning

confidence: 99%

Rock properties of the upper‐crust in Central Apennines (Italy) derived from high‐resolution 3‐D tomography

Monna

Filippi

Beranzoli

et al. 2003

Geophysical Research Letters

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[1] High-resolution 3-D P and S-wave velocity models of a central sector of the Apennines (Central Italy) are computed by inverting first arrival times from an aftershock sequence (September -December, 1997) following the M w 5.7 and M w 6.0 Umbria-Marche earthquakes that occurred on September 26, 1997. The high quality of the data set, especially for the S-wave, allows us to compute 3-D variations in V p , V p /V s and V p Á V s . The anomalies can be interpreted as lateral changes in rock type and fracturing, which control fluid diffusion and variation in pore pressure. This is in agreement with a poro-elastic view that can be inferred from the spatiotemporal evolution of the seismic sequence.

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“…In the internal (western) sector (Tuscan Domain), the compressional belt is disrupted by extensional deformations that generated several NW–SE graben systems filled by Neogene sediments (Lavecchia 1990; Collettini et al. 2000).…”

Section: Introductionmentioning

confidence: 99%

Regional groundwater flow and interactions with deep fluids in western Apennine: the case of Narni‐Amelia chain (Central Italy)

Frondini¹,

Cardellini²,

Caliro³

et al. 2011

Geofluids

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The elemental fluxes and heat flow associated with large aquifer systems can be significant both at local and at regional scales. In fact, large amounts of heat transported by regional groundwater flow can affect the subsurface thermal regime, and the amount of matter discharged towards the surface by large spring systems can be significant relative to the elemental fluxes of surface waters. The Narni‐Amelia regional aquifer system (Central Italy) discharges more than 13 m3 sec−1 of groundwater characterised by a slight thermal anomaly, high salinity and high pCO2. During circulation in the regional aquifer, groundwater reacts with the host rocks (dolostones, limestones and evaporites) and mixes with deep CO2‐rich fluids of mantle origin. These processes transfer large amounts of dissolved substances, in particular carbon dioxide, and a considerable amount of heat towards the surface. Because practically all the water circulating in the Narni‐Amelia system is discharged by few large springs (Stifone‐Montoro), the mass and energy balance of these springs can give a good estimation of the mass and heat transported from the entire system towards the surface. By means of a detailed mass and balance of the aquifer and considering the soil CO2 fluxes measured from the main gas emission of the region, we computed a total CO2 discharge of about 7.8 × 109 mol a−1 for the whole Narni‐Amelia system. Finally, considering the enthalpy difference between infiltrating water and water discharged by the springs, we computed an advective heat transfer related to groundwater flow of 410 ± 50 MW.

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Seismic expression of active extensional faults in northern Umbria (Central Italy)

Cited by 35 publications

References 5 publications

Geodynamically induced variations in the emission of CO₂gas at San Faustino (Central Apennines, Italy)

Geodynamically induced variations in the emission of CO₂gas at San Faustino (Central Apennines, Italy)

Rock properties of the upper‐crust in Central Apennines (Italy) derived from high‐resolution 3‐D tomography

Regional groundwater flow and interactions with deep fluids in western Apennine: the case of Narni‐Amelia chain (Central Italy)

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Seismic expression of active extensional faults in northern Umbria (Central Italy)

Cited by 35 publications

References 5 publications

Geodynamically induced variations in the emission of CO2gas at San Faustino (Central Apennines, Italy)

Geodynamically induced variations in the emission of CO2gas at San Faustino (Central Apennines, Italy)

Rock properties of the upper‐crust in Central Apennines (Italy) derived from high‐resolution 3‐D tomography

Regional groundwater flow and interactions with deep fluids in western Apennine: the case of Narni‐Amelia chain (Central Italy)

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Geodynamically induced variations in the emission of CO₂gas at San Faustino (Central Apennines, Italy)

Geodynamically induced variations in the emission of CO₂gas at San Faustino (Central Apennines, Italy)