3-D Deep Electrical Resistivity Tomography of the Major Basin Related to the 2016 Mw 6.5 Central Italy Earthquake Fault

被引：14

作者：

Sapia, V ^{[1
]}

Villani, F. ^{[1
]}

Fischanger, F. ^{[2
]}

Lupi, M. ^{[3
]}

Baccheschi, P. ^{[1
]}

Pantosti, D. ^{[1
]}

Pucci, S. ^{[1
]}

Civico, R. ^{[1
]}

Sciarra, A. ^{[1
]}

Smedile, A. ^{[1
]}

Romano, V ^{[4
]}

De Martini, P. M. ^{[1
]}

Murgia, F. ^{[4
]}

Materni, V ^{[1
]}

Giannattasio, F. ^{[1
]}

Pizzimenti, L. ^{[5
]}

Ricci, T. ^{[1
]}

Brunori, C. A. ^{[1
]}

Coco, I ^{[1
]}

Improta, L. ^{[1
]}

机构：

[1] Ist Nazl Geofis & Vulcanol, Rome, Italy

[2] Geostudi Astier, Livorno, Italy

[3] Univ Geneva, Dept Earth & Environm Sci, Geneva, Switzerland

[4] Univ Roma La Sapienza, Dept Earth Sci, Rome, Italy

[5] Soft Strategy Grp SpA, Rome, Italy

来源：

TECTONICS | 2021年 / 40卷 / 04期

关键词：

extensional basin; fault‐ zone imaging; Fullwaver; normal fault detection; M-w; 6; 5 Norcia Earthquake; SEISMIC HAZARD; ACTIVE EXTENSION; QUATERNARY BASIN; APENNINES; AREA; EVOLUTION; GEOMETRY; SEQUENCE; PALEOSEISMOLOGY; DEPOSITS;

D O I：

10.1029/2020TC006628

中图分类号：

P3 [地球物理学]; P59 [地球化学];

学科分类号：

0708 ; 070902 ;

摘要：

We provide the first 3-D resistivity image of the Pian Grande di Castelluccio basin, the main Quaternary depocenter in the hangingwall of the Mt.Vettore-Mt. Bove normal fault system (VBFS), responsible for the October 30, 2016 M-w 6.5 Norcia earthquake (central Italy). The subsurface structure of the basin is poorly known, and its relation with the VBFS remains debated. Using the recent Fullwaver technology, we carried out a high-resolution 2-D transect crossing the 2016 coseismic ruptures coupled with an extensive 3-D survey with the aim of: (a) mapping the subsurface of the basin-bounding splays of the VBFS and the downdip extent of intrabasin faults; (b) imaging the infill and pre-Quaternary substratum down to similar to 1 km depth. The 2-D resistivity section highlights under the coseismic ruptures a main dip-slip fault zone with conjugated splays. The 3-D resistivity model suggests that the basin consists of two depocenters (similar to 300 and similar to 600 m deep, respectively) filled with silty sands and gravels (resistivity <300 ohm m), bounded and cross-cut by NNE-, WNW-, and NNW-trending faults with throws of similar to 200-400 m. We hypothesize that the NNE-trending system acted during the early basin development, followed by NNW-trending and currently active splays of the VBFS that overprint pre-existing structures and locally control the infill architecture. Moreover, beneath the basin we detect a shallow NW-dipping blind fault. The latter is likely a hangingwall splay of the adjacent regional Mts. Sibillini Thrust, which may have been partly involved in the rupture process of the Norcia mainshock.

引用

页数：19

共 70 条

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