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

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.

Seismic architecture, stratigraphy and evolution of a subtropical marine embayment: Maputo Bay, Mozambique

“…truncation event most likely associated with a tropical cyclone, a common occurrence within the region (Matyas, 2014). Several large lagoon and embayed water bodies of the US Atlantic show a similar erosional truncation of their fills by tempestite horizons (Liu and Fearn, 1993;McCloskey and Liu, 2013); such a feature need only to form in areas that occur along regular hurricane or cyclone pathways.…”

“…Surface 7 shares many of the attributes of hurricane-generated erosion surfaces identified in similar lagoonal settings (e.g., McCloskey and Liu, 2013). These include the presence of concentrated autochthonous shell debris, capping of the upper surface of the deposit by a lining of concave-up shell layers and an overall fining upward succession.…”

Tropical cyclone activity enhanced by Sahara greening and reduced dust emissions during the African Humid Period

“…Such archives have so far provided information as far back as the midHolocene (MH; 7,000-4,000 yBP). Paleotempest records from the western North Atlantic have shown that the frequency of intense hurricanes may have fluctuated considerably during the last 7,000 y under varying climatic conditions (20)(21)(22)(23). However, most of the proxy records span only a few millennia and are limited to specific locations where individual TCs happened to make landfall.…”

Sedimentary History of Mangrove Cays in Turneffe Islands, Belize: Evidence for Sudden Environmental Reversals

“…These dates were calibrated to calendar years using the Calib 6.0 program (Stuiver, Reimer, and Reimer, 2010), based on the datasets of Reimer et al (2009). An age-depth model was created using a single calendar date for each sample by averaging the midpoints of all sigma date ranges, weighted by probability (McCloskey and Liu, 2013).…”

“…Three hurricanes (Unnamed, 1931, category 3;Hattie, 1961, category 5;Keith, 2000, category 4) have passed within 10 km at category 3 strength or higher during the last 80 years. Long-term hurricane landfall records indicate that the average strike probability has been~one major storm per decade for the coast of Belize over the last 500 years (McCloskey and Keller, 2009) and that such storms have been frequent occurrences for at least the last 7000 years (McCloskey and Liu, 2013). The effects of Hurricane Hattie, which crossed Turneffe Islands as a category 5 hurricane in 1961, are described in detail by Stoddart (1963).…”