Thursday, January 24, 2013

New paper finds hurricanes in Belize were more active in the distant past

A paper published today in The Holocene reconstructs hurricane activity in Belize over the past 7,000 years and finds the most active periods were in the distant past. According to the authors, the most active periods occurred "during ~200–600 BP [BP = years before the present], 1450–2600 BP, 3200–4200 BP, 4750–5450 BP, 5750–6050 BP, and 6700–6900 BP."


A 7000 year record of paleohurricane activity from a coastal wetland in Belize

  1. Terrence A McCloskey
  2. Kam-biu Liu
  1. Louisiana State University, USA
  1. Terrence A McCloskey, Department of Oceanography and Coastal Sciences, School of the Coast and Environment, Louisiana State University, Baton Rouge LA 70803, USA. Email: tmcclo1@tigers.lsu.edu

Abstract

Sedimentary paleotempestological studies have documented that tropical cyclone activity levels in the North Atlantic have been characterized by significant fluctuations since at least the mid Holocene, with activity regimes typically lasting from several centuries to > 2000 years. These activity-level estimates are based on site-specific hurricane strike histories derived from proxy records of overwash events attributed to landfalling major hurricanes. Here we present a 7000 year composite record from two adjacent wetland sites in coastal Belize, Central America that records both tropical cyclone-generated storm surges and large precipitation events. Although overall sensitivity appears to decrease over time, this record displays clear evidence of continuous oscillation between distinctly different activity regimes, with active and quiet periods each covering ~ 50% of the record. Active periods occur during ~200–600 BP, 1450–2600 BP, 3200–4200 BP, 4750–5450 BP, 5750–6050 BP, and 6700–6900 BP. This activity pattern does not match regional records from the northern Gulf of Mexico, the northern Caribbean or the Atlantic coast of the USA, thereby supporting the view that activity patterns are temporally variable throughout the North Atlantic, and that hyperactivity does not occur simultaneously across the entire basin.

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