HR: 1330h
AN: T52A-0236    [PDF]
TI: GPS measurements of crustal deformation across the northern Apennines, northern Italy
AU: * Bennett, R A
EM: rbennett@cfa.harvard.edu
AF: Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, MS 42, Cambridge, MA 02138
AU: Elosegui, P
EM: pelosegui@cfa.harvard.edu
AF: Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, MS 42, Cambridge, MA 02138
AU: Normandeau, J E
EM: jnormand@cfa.harvard.edu
AF: Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, MS 42, Cambridge, MA 02138
AU: Serpelloni, E
EM: serpelloni@bo.ingv.it
AF: Instituto Nazionale di Geofisica, Via D. Creti, 12, Bologna, 40127 Italy
AB: Continuous GPS stations within and around the northern Apennines, northern Italy, provide sparse but very precise constraints on crustal deformation associated with Africa, Eurasia, and Adriatic plate interactions. We analyzed data acquired by these stations during the time period of 1996 to 2003.5, finding distributed northwest range-parallel crustal shortening, totaling some 2 mm/yr, and northeast directed crustal extension across the Apennines hinterland, totaling 2.5--3.0 mm/yr or more. Extensional strain rates vary as a function of latitude within the northern Apennines, with higher strain rates across a narrow belt in the central part of the northern Apennines (latitude $\sim$43N) and lower strain rates across a broader zone further north (latitude $\sim$44N). Northeast directed crustal extension is prominent in the geology and seismicity of the Apennines hinterland, and forms an important observational basis for contemporary geodynamical models describing present-day deformation processes in northern Italy. Range-parallel crustal shortening is less well understood, however, because there are very few geological or seismological indicators of northwest directed crustal shortening for the northern Apennines. On the other hand, combined paleomagnetic and tomographic inferences suggest that the northern Apennines is an orocline, achieving its arcuate shape as a result of progressive bending of an originally straight orogen. The rates and patterns of range-parallel deformation may thus provide important new constraints on geodynamical models for this complex region.
DE: 1206 Crustal movements--interplate (8155)
DE: 1208 Crustal movements--intraplate (8110)
DE: 8102 Continental contractional orogenic belts
DE: 8107 Continental neotectonics
DE: 8110 Continental tectonics--general (0905)
SC: Tectonophysics [T]
MN: 2003 Fall Meeting