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Spectral properties of volcanic materials in the optical region (350-2500 nm) of the electromagnetic spectrum are analyzed. The goal is to characterize air-fall deposits, recent lava flows, and old lava flows based on their spectral reflectance properties and on the textural characteristics (grain size) of pyroclastic deposits at an active basaltic volcano. Data were acquired during a spectroradiometric field survey at Mt. Etna (Italy) in summer 2003 and combined with hyperspectral satellite (Hyperion) and airborne LiDAR (Light Detection and Ranging) data. In addition, air-fall deposits produced by the highly explosive 2002-2003 eruption have been sampled and spectrally characterized at different distances from the new vents. The spectral analysis shows that air-fall deposits are characterized by low reflectance values besides variations in grain size. This distinguishes them from other surface materials. Old lava flows show highest reflectance values due to weathering and vegetation cover. The spectral data set derived from the field survey has been compared to corrected satellite hyperspectral data in order to investigate the Hyperion capabilities to differentiate the surface cover using the reflectance properties. This has allowed us to identify the 2002-2003 air-fall deposits in a thematic image just few months after their emplacement. Moreover, the observed differences in the field spectra of volcanic surfaces have been compared with differences in the signal intensity detected by airborne LiDAR survey showing the possibility to include information on the texture of volcanic surfaces at Mt. Etna. The approach presented here may be particularly useful for remote and inaccessible volcanic areas and also represents a potentially powerful tool for the exploration of extraterrestrial volcanic surfaces.

The Ml=5.8 (Mw=6.2) earthquake that struck and devastated a broad area in the Abruzzi region of Central Italy produced a large set of surface coseismic deformations. In this work we present the field geological survey performed by the researchers involved in the EmerGeoWorking Group following the mainshock. The activities in the field consisted in the control and the characterization of the surface coseismic deformations mainly observed along previously mapped faults; in addition, a number of local coseismic effects are reported (landslides and secondary fractures) that are not directly associated to tectonic structures. A total of more than 300 sites of observation were surveyed in an area of ~900 km2. A preliminary analysis of our observations indicates that the ruptures reported along the Paganica Fault may represent the surface expression of the fault responsible for the April 6th mainshock, and that the effects observed along the Bazzano and Monticchio-Fossa Faults may reflect the coseismic reactivation of an antithetical structure.

The field measurements campaign made in July 2003 on Etna, Vulcano Island and Campi Flegrei was dedicated to the calibration and validation of airborne and spaceborne data. The campaign activities were relevant part of two ASI funded projects: 1) FASA, dedicated to airborne system and data validation/calibration 2) HypSEO, dedicated to multispectral an hyperspectral spaceborne data validation/calibration on specific test areas. The airborne campaign was organized in the frame of a three-year project funded by ASI and DLR as it represented the flight test of the FASA system, which combines a Fourier interferometer in the MIR-TIR region and an imager (ABAS). The main objectives of this proposal are: 1. Design and implementation of an airborne system for the Fourier Spectrometer MIROR and ABAS (Bird Airborne Simulator); 2. Airborne Operational tests of the FASA system over the main Italian volcanic areas (i.e. Etna, Stromboli and Vulcano) and possibly on controlled forest fires (Germany); 3. Organization of the necessary ground campaign for calibration and validation of the acquired data; 4. Development of the algorithms for the selection of the “spectral windows” and for the determination of the presence of some gasses: in particular SO2, CO2, H2S and other gasses of volcanic origin.

SUMMARY We studied fault scarps along the northern sector of the Celano–L'Aquila fault system in the Abruzzi region (central Apennines). Up to ∼9.5 km long, 3 m high, fault scarp traces mark the slope foot of ridgetop valleys at Mt Ocre range. In order to provide direct evidence of the deformation history of these scarps, we initiated geomorphic, ground-penetrating radar (GPR) and trenching investigations. GPR investigations yielded subsurface stratigraphic features of the scarp zones, and determined the locations for trenching sites. A total of five trenches were excavated at two different sites. Structural and stratigraphic analysis of the trench exposures combined with historical considerations, showed three faulting events between 5620 BC and 1300 AD; the most recent of them occurred after 1690 BC. Each of these events produced an estimated minimum vertical displacement ranging between 0.3 and 0.5 m. Our interpretation is that the Mt Ocre fault branch represents the northernmost surface expression of a single 35 km long seismogenic structure associated with M∼ 7 earthquakes. Any attempt to estimate the seismic hazard in the area must consider the presence of this important source.