Thesis advisor: Amy Frappier / Tropical cyclones (TCs), known as hurricanes in the Atlantic and Typhoons in the Pacific, are among the most destructive and deadly natural disasters that occur on Earth. Attempts to understand how TCs relate to the global climate system, and future risk assessments are dependent upon having records of TC activity that pre-date the modern meteorological records, which are commonly not older than 130 years (Nott, 2003). Paleotempestology is a sub-discipline of paleoclimatology that attempts to extend the TC record beyond the meteorological record through the use of proxies. Presented here is the establishment of a paleotempestology proxy based on clastic mud being suspended in the water column by floods caused by TCs and deposited in stalagmite CH-1, collected in June of 2007 from Cenote Chaltun-Ha, a low-lying cave from the Yucatán Peninsula. CH-1 was dated by a combination of <super>210</super>Pb, U/Th, and layer counting techniques, creating an age model for its entire length. The years with mud layers were compared to the historical TC record from 1852-2006. Nineteen mud layers were identified for this time period. All of the mud layers deposited in years with at least one TC passing within 330 km of Cenote Chaltun-Ha. A total of 265 mud layers were identified in CH-1 dating from 198 BC to 2006 AD. Relatively high TC frequency, ~16 mud layers/century, was recorded in CH-1 from 198 BC to ~1233 AD. This period was followed by eight centuries of relatively low TC frequency, ~7 mud layers/century. The low frequency period hit a low point in the 1600s with 4 mud layers. Since the 1600s the TC frequency recorded in CH-1 has been on the rise, indicating possible periods of higher than present TC frequency in the future for the Yucatán region. This trend of high TC frequency followed by a sudden drop and subsequent increase is also reported in published sand overwash deposit research. δ;<super>18</super>O and δ;<super>13</super> values collected from CH-1 provide insight into the timing of regional droughts. A low δ;<super>18</super>O value from 1815 provides evidence that "The Year Without a Summer" caused by the 1815 eruption of the Tambora volcano in Indonesia had a climatic effect on the Yucatán. A land-use signal related to the agricultural production boom of Agave Fourcroydes, a succulent plant known as Henequen, in the early 20th century was also detected in δ;<super>13</super>C values. / Thesis (MS) — Boston College, 2010. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Geology and Geophysics.
| Identifer | oai:union.ndltd.org:BOSTON/oai:dlib.bc.edu:bc-ir_101853 |
| Date | January 2010 |
| Creators | Pyburn, James |
| Publisher | Boston College |
| Source Sets | Boston College |
| Language | English |
| Detected Language | English |
| Type | Text, thesis |
| Format | electronic, application/pdf |
| Rights | Copyright is held by the author, with all rights reserved, unless otherwise noted. |
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