GSA DATA REPOSITORY

GSA DATA REPOSITORY 2011171 Analysis of large, seismically induced gravitational deformations imaged by high resolution COSMO-SkyMed SAR Moro M. 1, Chini M. 1, Saroli M. 1,2, Atzori S. 1, Stramondo S. 1 and Salvi S. 1 1 Istituto Nazionale di Geofisica e Vulcanologia, Centro Nazionale Terremoti, Roma, Italy 2 Dipartimento di Meccanica, Strutture, Ambiente e Territorio, University of Cassino, Cassino, Italy Data repository Item DR1: Seismotectonic framework and geological setting. The present structure of the Central Apennine chain is the result of the NNW-SSE convergence between Africa and Eurasian plates (De Mets et al., 1990), and it has evolved through the contemporaneous back-arc opening of the Tyrrhenian sea and the eastward migration of the Apenninic fold and thrust belt, due to the flexural-hinge retreat of the Adria plate since the Neogene period (Malinverno and Ryan, 1986; Royden et al., 1987; Patacca et al., 1990; Doglioni, 1995; Meletti et al., 2000; Patacca and Scandone, 2001). Crustal shortening and thrusting was contemporaneously followed by extensional tectonics and its uplift (Bally et al., 1986; Galadini et al., 2003 and references therein). Extensional tectonics has affected the Apennines since the Pliocene, causing normal faults to dissect the Pliocene and Quaternary continental deposits (e.g. Meletti et al., 1995; Doglioni, 1995) and generating several extensional intermontane basins (Fig. DR1.1). Focal mechanisms, geodetic and borehole breakout data (Mariucci et al., 1999, D'Agostino et al., 2001, Chiaraluce et al., 2003) have been indicating an actual NE trending extensional stress field, related to the persistence of back-arc extension. The extensional activity, mainly concentrated along the axial belt, have produced NW-SE trending, SW-dipping, seismically active normal faults, bounding graben and half-graben basins (Galadini and Galli, 2000). The area of interest is located in the northern portion of the Abruzzi Apennine, south of the Gran Sasso massif. This sector belongs to the African continental crust and represents the external part of central Apennines, which is characterized by carbonatic sequences and transitional pelagic deposits. The area is bounded by the Mt. Sirente - Mt. Ocre alignment, in the SW side, and by Gran Sasso massif, in the NE side (Fig. DR1.1). The sector is characterized by the tectonic superimposition of units belonging to different paleogeographic domains, according to a thrust system. Moreover sedimentary basins have been developed on top of the above mentioned units. During the Miocene-Pliocene age the tectonic compression phase has been developed by means of a fold and thrust system. In this period the external compression front has migrated progressively toward E-NE (Lavecchia, 1988 and Patacca et al., 1990). It is possible to distinguish three main tectono-sedimentary units, superimposed by thrust faults and characterized by an Adriatic verging. The first one is Mt. Cefalone unit, which is

the more internal and characterized by Mesozoic carbonatic deposits (Jurassic). The second unit is Mt. Cagno, characterized by cretaceous platform terms on which are onlap placed miocenic deposits. The third one and the most external, it is the Mt. Ruzza - Mt. delle Macchie unit (within the Gran Sasso - Mt. Genzana unit), composed by various succession of different depositional environments. Moreover, the latter is characterized by marginal facies of pelagic sedimentation starting from the middle Lias. The entire sector has been involved in the upper Messinian-pliocenic deposition of conglomerates. During the Pleistocene and Olocene the area has been characterized by alluvial and lacustrine sedimentation (sands, silt, gravel and conglomerates) and slope deposits (breccias). The tectonic structure is characterized by two main front thrust. The first one, known as Mt. Orsello-Mt. Rotondo thrust, is Apenninic striking and it is responsible of the superimposition of the Mt. Cefalone unit on the Mt. Cagno one. The second front thrust, Mt. d Ocre - Mt. Cagno, causes a further superimposition of the Mt. Cagno unit on the Mt. Ruzza - Mt. delle Macchie one. The main plio-quaternary normal faults show a NW-SE and NNW-SSE strike and are parallel to the main structural axis of the chain. Other WNW-ESE trending faults are present in the Gran Sasso massif. References: Bally, A. W., Burbi, L., Cooper, C., Ghelardoni, R., 1986. Balanced sections and seismic reflection profiles across the central Apennines. Mem. Soc. Geol. It. 35, 257-310. Chiaraluce, L., Ellsworth, W.L., Chiarabba, C., Cocco, M., 2003. Imaging the complexity of an active normal fault system: The 1997 Colfiorito (central Italy) case study. J. Geophys. Res. 108, 2294. D'Agostino, N., Giuliani, R., Mattone, M., Bonci, L., 2001. Active crustal extension in the central Apennines (Italy) inferred from GPS measurements in the interval 1994 1999. Geophys. Res. Lett. 28, 2121. De Mets, C., Gordon R.G., Argus, D. F. and Stein, S., 1990. Current plate motions. Geophys. J. Int., 101, 425-478. Doglioni, C., 1995. Geological remarks on the relationships between extension and convergent geodynamic settings. Tectonophysics 252, 253 267. Galadini, F., Galli, P., 2000. Active tectonics in the central Apennines (Italy) input data for seismic hazard assessment. Natural Hazards 22, 225 270. Galadini, F., Messina, P., Giaccio, B., Sposato, A., 2003. Early uplift history of the Abruzzi Apennines (central Italy): available geomorphological constraints. Quaternary International 101/102, 125-135. Malinverno, A., Ryan, W.B.F., 1986. Extension in the Tyrrhenian sea and shortening in the Apennines as result of arc migration driven by sinking of the lithosphere. Tectonics 5, 227 245.

Mariucci, M.T., Amato, A., Montone, P., 1999. Recent tectonic evolution and present stress in the northern Apennines (Italy). Tectonics 18, 108 118. Meletti, C., Patacca, E., Scandone, P., 2000. Construction of a seismotectonic model: the case of Italy. Pure and Applied Geophysics 157, 11 35. Patacca, E., Sartori, R., Scandone, P., 1990. Tyrrhenian basin and apenninic arcs: kinematic relations since Late Tortonian times. Mem. Soc. Geol. It. 45, 425 451 Patacca, E., Scandone, P., 2001. Late thrust propagation and sedimentary response in the thrustbelt-foredeep system of the southern Apennines (Pliocene-Pleistocene). In: Vai, G.B., Martini, I.P. (Eds.), Anatomy of an Orogen: the Apennines and Adjacent Mediterranean Basins. Kluwer Academic Publishers, Dordrecht, pp. 401 440. Royden, L., Patacca, E., Scandone, P., 1987. Segmentation and configuration of subducted lithosphere in Italy: an important control on thrust-belt and foredeep-basin evolution. Geology 15, 714 717. Fig. DR1.1 Simplified geological and structural map of the central Apennines. Key to legend: 1) marine and continental clastic deposits (Pliocene-Quaternary); 2) volcanic deposits (Pleistocene); 3) synorogenic hemipelagic and turbiditic sequences (Tortonian-Pliocene); 4) carbonate platform deposits (Trias-Miocene); 5) slope and pelagic deposits (Lias-Miocene); 6) main thrust; 7) main normal and/or strike-slip fault; 8) study areas.

Fig. DR1.2 Simplified geological and structural map of the study area. Legend: 1) Mt. Cefalone Unit; 2) Mt. Cagno Unit; 3) Mt. Ruzza-Mt. Delle Macchie Unit; 4) quaternary Unit; 5) thrust; 6) normal fault.

Fig. DR1.3 Geological map of the Colle Campetello area. Key to legend: 1) Calcari a Requiene Formation; Calcare a Rudiste Formation; Calcari a radiolariti Formation; (Lower-Upper Cretaceus); 2) Calcari a Calcispherulidi (Upper Cretaceus); 3) Scaglia detritica ad Orbitoides Formation (Upper Cretaceus); 4) Calcari a Nummuliti e Discolcycline (Lower Paleocene); 5) Calcari a Miogypsine e Lepidocycline (Lower-Middle Paleocene); 6) Calcari spongoliti Unit (Lower-Middle Miocene); 7) Calcari a Briozoi e Litotamni (Middle Miocene); 8) Supersintema di Aielli-Pescina alluvial deposits (Pliocene-Pleistocene); 9) debris and alluvial fan (Pleistocene-Holocene); 10) talus and alluvial deposits (Pleistocene-Holocene); 11) fault; 12) inferred normal and strike slip faults; 13) thrust; 14) inferred thrust; 15) strike and dip of bedding; 16) collapsed sinkhole; 17) altitude abouve sea level to meter.

Fig. DR1.4 Geological map of the Colle Clinelle area. Key to legend: 1) Dolomia principale Formation; CalcareMassiccio Formation; Corniola Formation; (Trias-Giurassico); 2) Scaglia detritica Formation (Lower Eocene); 3) Scaglia cinerea Formation (Middle Eocene); 4) Bisciaro Formation (Upper Eocene-Lower Miocene); 5) clay and hemipelagic marls Unit (Upper Miocene); 6) alluvial deposits (Pleistocene-Holocene); 7) tallus complex (Pleistocene-Holocene); 8) debris and alluvial fan (Pleistocene-Holocene); 9) fault; 10) inferred normal and strike slip faults; 11) strike and dip of bedding; 12) shear zone and inferred shear zone; 13) altitude abouve sea level to meter.

Data repository Item DR2: Geomorphologic evidences of large gravitational deformations. We carried out a detailed photogeological analysis over the areas where anomalous surface deformations were observed. Such analysis allowed us to identify widespread evidence of morphological elements associated with large gravitational deformation (Figs. DR2.1 and DR2.2), as double crest lines, scarps and counter-slope scarps, trenches, fractures, and depression alignments. Below, we provide aerial photograph interpretation of the main features observed Fig. DR2.1 Observed features of the Colle Campetello large gravitational deformation from the interpretation of aerial photographs.

Fig. DR2.2 Observed features of the Colle Clinelle large gravitational deformation from the interpretation of aerial photographs.

Data repository Item DR3 As mentioned in the text, we assume that the Colle Clinelle and Colle Campetello deformations have been nearly instantaneous. We base such assumption on the following considerations. Using a DInSAR data set covering the time period 1992-2001 (published in Hunstad et al, 2009) we verified that at least Colle Campetello was not undergoing any significant deformation before the earthquake (see figure below). Unfortunately we have no similar coverage for the Colle Clinelle area. Colle Campetello Figure DR3.1 Ground velocities in the Colle Campetello area estimated from a large SAR image data set in the period 1992-2001, see Hunstad et al., 2009 for details. Then using at least three post-seismic interferograms covering 8, 9, and 30 days after the quake, we verified that both areas did not move after April 12. Therefore we assume that the two areas have not undergone significant, time-dependent plastic (or viscous) deformation before and after the earthquake, where "significant" means larger than 1 mm/yr before the earthquake, and larger than 2-3 mm in 30 days, for the post earthquake. We invert the LoS observations of ground displacement, using the procedure described in Atzori et al, 2009, and references therein. In order to model the dislocation geometry with respect to the actual topography, we include the parameter Elev, i.e. the elevation a.s.l. of each observation point, using the procedure described in Lungarini et al, 2005. Given the inherent approximations of the elastic modeling procedure, we only tested planar dislocation surfaces.

We provide the following files: [colle_camp_sliding_values.txt]: Table containing the parameters of the 180 patches used to describe the sliding values of the Colle Campetello shearing plane. The following fields are provided: Length_m: length of the patch [m] Width_m: width of the patch [m] Top_d_m: depth of the patch top edge, with positive values direct inside the earth [m] Strike_d: Azimuth of the patch from north [deg] Dip_d: Dipping angle from the horizontal [deg] Coorde_m: UTM-WGS84, zone 33, east coordinate of the patch centre [m] Coordn_m: UTM-WGS84, zone 33, north coordinate of the patch centre [m] Rake_d: Direction of the sliding displacement, adopting the Okada convention [deg] Slip: Sliding value of the patch [cm] [colle_campetello.txt]: Table of the 2524 points regularly sampled from the DInSAR interferogram. The following fields are provided: East: UTM-WGS84, zone 33, east coordinate [m] North: UTM-WGS84, zone 33, north coordinate [m] Elev: Elevation above the sea level [m] Observed: Displacement value in the radar line-of-sight [cm] Shift_tilt: Contribution to the modelled displacement from ramps and offset [cm] Source: Contribution to the modelled displacement from the distributed sliding values [cm] Modeled: Total modelled displacement, i.e. Shift_tilt + Source [cm] Residual: Observed minus modelled displacement values [cm] Sigma: Generic sigma value of the observed displacement [cm] Coef_east : East component of the radar line-of-sight Coef_north: North component of the radar line-of-sight Coef_up: Vertical component of the radar line-of-sight [colle_cli_sliding_values.txt]: Table containing the parameters of the 70 patches used to describe the sliding values for the Colle Clinelle shearing plane. Fields provided are the same of [colle_camp_sliding_values.txt] [colle_clinelle.txt]: Table of the 3150 points regularly sampled from the DInSAR interferogram. Fields provided are the same of [colle_campetello.txt]. References: Atzori, S., I. Hunstad, M. Chini, S. Salvi, C. Tolomei, C. Bignami, S. Stramondo, E. Trasatti, A. Antonioli, and E. Boschi (2009), Finite fault inversion of DInSAR coseismic displacement of the 2009 L'Aquila earthquake (central Italy), Geophys. Res. Lett., 36, L15305, doi:10.1029/2009gl039293. Lungarini, L., Troise, C., Meo, M. and De Natale, G., 2005, Finite element modelling of topographic effects on elastic ground deformation at Mt. Etna: Journal of Volcanology and Geothermal Research., v. 144, p. 257-271.