The Earth Science Colloquium Series presents:
Land subsidence: Causes, measurements, and implications for the world’s growing urban population
with Dr. Shimon Wdowinski, Professor, Earth and Environment, Florida International University.
Abstract: Land subsidence, the lowering of the land-surface elevation, occurs at a variety of temporal and spatial scales in various cover areas. It is most noticeable in urban and suburban areas, as small changes in surface elevation can impact both infrastructure and human well-being. Causes for land subsidence include both natural (e.g., tectonics, sediment compaction) and anthropogenic (e.g., fluid extraction, soil consolidation) processes. Space geodetic techniques, in particular Global Navigation Satellite System (GNSS) and Interferometric Synthetic Aperture Radar (InSAR), provide a wide range of measurement scales that can monitor many subsidence types.
The presentation will cover the main processes causing subsidence, the geodetic measurement techniques used for subsidence monitoring, and two examples of subsidence impact on large urban populations. The first example is inland subsidence in central Mexico, which is characterized by high subsidence rates (up to 400 mm/yr) and affects millions of people. The second example is coastal subsidence along the US Atlantic and Gulf coasts, which is relatively slow (order of 2-10 mm/yr), but when combined with rising sea levels (>3 mm/yr), can significantly contribute to coastal flooding hazards. Geodetic subsidence monitoring also provides tools for remote monitoring of infrastructure and building stabilities, which can help secure safer environments for the world’s increasing urban population.
Host: Dr. James Davis, Lamont Research Professor, Seismology, Geology and Tectonophysics.
