HR: 08:00h
AN: T51E-01 INVITED     [Abstracts]
TI: CAT/SCAN, the Calabria-Apennine-Tyrrhenian/Subduction -Accretion-Collision Network
AU: * Steckler, M S
EM: steckler@ldeo.columbia.edu
AF: Lamont-Doherty Earth Observatory of Columbia University, 61 Route 9W, Palisades, NY 10964
AU: Amato, A
AF: Istituto Nazionale di Geofisica e Vulcanologia, Via di Vigna Murata, 605, Roma, 00143 Italy
AU: Guerra, I
AF: Dipartimento di Fisica, Universit… della Calabria Via P. Bucci, Cosenza, 87040 Italy
AU: Di Luccio, F
AF: Istituto Nazionale di Geofisica e Vulcanologia, Via di Vigna Murata, 605, Roma, 00143 Italy
AU: Lerner-Lam, A
AF: Lamont-Doherty Earth Observatory of Columbia University, 61 Route 9W, Palisades, NY 10964
AU: Persaud, P
AF: Lamont-Doherty Earth Observatory of Columbia University, 61 Route 9W, Palisades, NY 10964
AU: Seeber, L
AF: Lamont-Doherty Earth Observatory of Columbia University, 61 Route 9W, Palisades, NY 10964
AU: Armbruster, J
AF: Lamont-Doherty Earth Observatory of Columbia University, 61 Route 9W, Palisades, NY 10964
AU: Tolstoy, M
AF: Lamont-Doherty Earth Observatory of Columbia University, 61 Route 9W, Palisades, NY 10964
AU: Cimini, G B
AF: Istituto Nazionale di Geofisica e Vulcanologia, Via di Vigna Murata, 605, Roma, 00143 Italy
AU: Piromallo, C
AF: Istituto Nazionale di Geofisica e Vulcanologia, Via di Vigna Murata, 605, Roma, 00143 Italy
AU: Di Maro, R
AF: Istituto Nazionale di Geofisica e Vulcanologia, Via di Vigna Murata, 605, Roma, 00143 Italy
AU: D'Anna, G
AF: Istituto Nazionale di Geofisica e Vulcanologia, Via di Vigna Murata, 605, Roma, 00143 Italy
AU: Gervasi, A
AF: Dipartimento di Fisica, Universit… della Calabria Via P. Bucci, Cosenza, 87040 Italy
AU: De Rose, C
AF: Dipartimento di Fisica, Universit… della Calabria Via P. Bucci, Cosenza, 87040 Italy
AB: Calabria, the toe of Italy, is bordered on the south by the Calabrian Arc with northward subduction of the Ionian Sea. Seismicity of the subducting slab extends to 400 km depth, but is restricted to a compact arc with well-defined edges. Calabria is an exotic block that rifted off from Sardinia and Corsica opening the Tyrrhenian Sea backarc basin in its wake. The rapid SE advance of this island arc with subduction ahead and extension behind is believed to be driven by rollback of the old Mesozoic seafloor of the Ionian Sea. Progressive collision of the arc with Adria formed the Apennines, the mountainous backbone of Italy. Collision of the arc with Africa formed the Maghrebides in Sicily. The Calabrian Arc is the last remaining piece of oceanic subduction. However, the rapid advance of the arc has slowed, or possibly even halted, by these collisions. Calabria and the surrounding region, meanwhile, have been undergoing rapid uplift as a result of the evolving tectonics. Whether rollback of the oceanic lower plate of the Ionian Sea continues and whether the upper plate of Calabria continues to move as an independent plate are both uncertain. The answer will provide insight into the relative forces involved in rollback and collision. The progressive collisions on either side of Calabria have been steadily decreasing the negative buoyancy of the subducting slab while increasing collision resistance. CAT/SCAN, the Calabria-Apennine-Tyrrhenian/Subduction-Accretion-Collision Network, is a multidisciplinary effort to understand the tectonics and dynamics of the region. The first phase is a passive seismic experiment designed to image the structure of southern Italy. CAT/SCAN I consists of an array of 39 broadband seismometers onshore, deployed in the winter of 2003/4 and 12 broadband Ocean Bottom Seismometer deployed in Oct. 2004. All instruments will remain deployed until Sept. 2005. Across strike, the experiment will determine the structure of the entire Calabrian subduction and southern Apennine collision systems from the incoming plate to the arc, slab and backarc spreading system. Along strike, the experiment will map the structure of the transition from oceanic subduction in Calabria to continental collision in the southern Apennines. The experiment is also ideally positioned to detect proposed patterns of mantle flow related to possible slab gaps and Tyrrhenian extension. We will discuss the goals of the project, present and future experiments and initial results.
UR: http://satchmo.ldeo.columbia.edu/res/pi/catscan/index.html
DE: 8102 Continental contractional orogenic belts
DE: 8123 Dynamics, seismotectonics
DE: 8158 Plate motions--present and recent (3040)
DE: 7200 SEISMOLOGY
DE: 7218 Lithosphere and upper mantle
SC: Tectonophysics [T]
MN: 2004 AGU Fall Meeting