HR: 09:45h
AN: G21D-08    [Abstracts]
TI: Assessing Past and Future Local Sea Level Rise in Venice, Italy: A Complex Balance of Vertical Land Motion, Atmospheric Forcing, and Oceanic Contributions
AU: * Plag, H
EM: hpplag@unr.edu
AF: Nevada Bureau of Mines and Geology, University of Nevada, Reno MS178, Reno, NV 89557-0088 United States
AU: Hammond, W C
EM: whammond@unr.edu
AF: Nevada Bureau of Mines and Geology, University of Nevada, Reno MS178, Reno, NV 89557-0088 United States
AU: Tsimplis, M
EM: mnt@noc.soton.ac.uk
AF: James Rennell Division for Ocean Circulation, Southamption Oceanography Center, Empress Dock, SO14 3ZH United Kingdom
AB: We have carried out an appraisal of the sea level rise scenarios for Venice, Italy in order to provide the scientific basis for mitigating the impact of future sea level rise. Based on a detailed analysis of past sea level variations and forcing factors, the components contributing to long period variations and secular changes in sea level in the upper Adriatic have been quantified. These factors include steric changes, ocean circulation, atmospheric forcing, mass changes in the large ice sheets, the continental glaciers, and the terrestrial hydrosphere, postglacial rebound, vertical land motion due to tectonics, sedimentation, sediment compaction, and peat oxidation, and man-made vertical land motion caused by groundwater, oil and natural gas extraction. Some of these factors act locally while other factors cause local sea level changes as a result of regional or global processes. In a balance of local sea level, all factors therefore have to be referred to the same geocentric reference frame. A main limitation in understanding the past contribution to local sea level changes arises from the large uncertainty in the observed geocentric vertical land motion, which is due to the uncertainties in the motion of the reference frame origin with respect to the geocenter. This uncertainty is estimated to be of the order of ± 1 mm/yr. For the appraisal of the sea level rise scenarios, each factor is projected over the next 100 years, taking into account the uncertainties in their past contribution as well as the uncertainties in their future developments. For several factors, different assumptions concerning the future developments are made, leading to different scenarios, covering a wide range of potential sea level developments for the next 100 years. All these scenarios are possible futures for the local sea level in Venice and the Lagoon, leaving a considerable uncertainty for the decision makers. In order to reduce the uncertainties, improved monitoring of vertical land motion and a better understanding of the underlying processes are required.
DE: 1223 Ocean/Earth/atmosphere/hydrosphere/cryosphere interactions (0762, 1218, 3319, 4550)
DE: 1641 Sea level change (1222, 1225, 4556)
DE: 4556 Sea level: variations and mean (1222, 1225, 1641)
DE: 9335 Europe
SC: Geodesy [G]
MN: Fall Meeting 2005