The role of tectonic depressions in floodplain development and in influencing the Source to Sink paradigm (Invited)
Abstract
Floodplain activity and location varies across historical and geological time, as influenced by sea level fluctuations, climate, tectonics, and human activity. Classification schemes on the morphology of deltas are relatively well advanced, with recent schemas built on consistent globally available data. There has not been a similar classification paradigm put forth for world floodplains. Here we provide an initial survey of global floodplains using consistent space imagery and techniques developed largely outside of the geological community. We focus on surface morphology of Holocene floodplains as imaged by the SRTM interferometric synthetic aperture radar (InSAR). We examine the propensity of these floodplains to flood based on MODIS (Moderate-resolution Imaging Spectroradiometer) imagery acquired twice-daily since 2000, and NASA/JAXA’s Advanced Microwave Scanning Radiometer (AMSR-E) imagery acquired daily basis since mid-2002. Each of the 29 floodplains surveyed were noted for simple overarching patterns of landscape elements or floodplain architecture. The three large architectural features are coastal deltas, tectonic depressions and container valleys. Forty-one percent of the floodplains contain tectonic depressions. Almost all of these depressions contain lakes or flood annually. Satellite surveys show that many of these lakes are tied to the main river through tie-channels, allowing the seasonal flood wave to push sediment laden water into the lakes. These tectonically controlled lakes greatly affect the flux of sediment within the source to sink continuum.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2010
- Bibcode:
- 2010AGUFMEP54A..08S
- Keywords:
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- 0933 EXPLORATION GEOPHYSICS / Remote sensing;
- 1622 GLOBAL CHANGE / Earth system modeling;
- 1820 HYDROLOGY / Floodplain dynamics;
- 8002 STRUCTURAL GEOLOGY / Continental neotectonics