AAPG Annual Convention and Exhibition

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From Paleohurricanes Through Source to Sink Research: Highlighting Recent Coastal Geology Contributions From John B. Anderson


This paper reviews the recent work of John B. Anderson through the lense of the presenting author and former student. This includes coastal geology, sedimentology, paleotempestology, and global change based primarily on field-based data and observations. Specifically, this talk reviews several Texas coastal studies on mechanisms of erosion, coastal sediment budgets, hurricane impacts over centennial and millennial timescales, and source to sink evolution in response to eustatic changes. This work is critical towards furthering our understanding of the dynamics associated with sedimentary systems. Along the upper Texas coast, both natural and anthropogenic mechanisms of erosion were quantified, in an effort to determine whether current erosion rates are unprecedented over historic time. River damming has had a minimal impact on sediment delivery to the coast, while engineering structures designed to slow down beach erosion have starved downdrift areas of sand deposition. This work paved the way for a study, which determined the volumetric sand flux over geologic and historic timescales into a tidal delta along the upper Texas coast. The majority of this sand was derived from erosion of Galveston Island, and revealed that erosion of this barrier island has been significantly enhanced due to a combination of accelerated sea-level rise coupled with hurricanes over centennial relative to millennial timescales. Bays along the northwestern Gulf of Mexico also responded to episodes of Holocene sea-level rise by rapidly flooding, and bayhead deltas backstepped landward at high rates. Furthermore, the millennial scale rate of hurricane impacts along the upper Texas coast was quantified. Over the past ~5,000 years, the annual intense hurricane landfall probability for south Texas is ~0.46%. Similar long-term annual probabilities across the Gulf of Mexico suggest that intense hurricane activity over multimillennial periods has not varied significantly. The evolution of late Quaternary depositional systems along the Texas margin was examined over the last 125,000 years. This work demonstrated the complex response of coastal systems from sea-level and sediment supply variations.