Coastal Hazards from Tropical Cyclones and Extratropical Winter Storms Based on Holocene Storm Chronologies
Aware of past and future climate changes, the question arose whether modern instrumental data adequately reflect the chronology of tropical cyclones and extratropical winter storms for the period of the present eustatic sea level highstand (approx. the pa
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Coastal Hazards from Tropical Cyclones and Extratropical Winter Storms Based on Holocene Storm Chronologies S.M. May, M. Engel, D. Brill, P. Squire, A. Scheffers, and D. Kelletat
Abstract Aware of past and future climate changes, the question arose whether modern instrumental data adequately reflect the chronology of tropical cyclones and extratropical winter storms for the period of the present eustatic sea level highstand (approx. the past 6,000 years). For pre-instrumental times, geological and sedimentological methods have been applied at geo- and bioarchives such as coastal marshes, lagoons, washover features or beach ridges, showing a frequency of strong cyclones roughly every 100–300 years, which is in contrast to the high number of major cyclones recorded recently. Many of these palaeotempestological records are discontinuous or contain hiatuses and it may be difficult to evaluate whether these sections of the record represent quiet phases without major cyclones or simply erosion or fluctuations in the ability of an archive to record the signature of cyclones. Manifold questions are still unanswered: as the potential number of former cyclones may be stored in landforms and sediments, how can the intensity of these cyclones be identified? Is the crest height of beach ridges a good indicator for storm surge heights, air pressure, and cyclone categories? This paper reviews important achievements in palaeotempestology and discusses open questions of cyclone distribution, frequency and energy (i.e., hazard potential) in the last few decades and reconstructions of these parameters back into Mid-Holocene times.
S.M. May (*) • M. Engel • D. Brill • D. Kelletat Institute of Geography, University of Cologne, Albertus-Magnus-Platz, 50923 Cologne, Germany e-mail: [email protected] P. Squire • A. Scheffers Southern Cross GeoScience, Southern Cross University, PO Box 157 Lismore, NSW 2480, Australia e-mail: [email protected] C.W. Finkl (ed.), Coastal Hazards, Coastal Research Library 6, 557 DOI 10.1007/978-94-007-5234-4_20, # Springer Science+Business Media Dordrecht 2013
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Introduction
During the last decade the world has witnessed the massive economic, social, and ecological impacts of tropical cyclones in different ocean basins and countries. Our understanding of their occurrence patterns influences planning activities and risk analyses from calculating insurance premiums to developing conservation strategies. The ongoing intense debate on climate change seeks answers to questions whether the number of tropical cyclones has increased in the last 150 years (e.g., Knutson et al. 2010; Mumby et al. 2011) and if existing instrumental records capture the full natural variability of cyclone frequency and magnitude (Webster et al. 2005; Nott et al. 2007). The impact of cyclone activity in different ocean basins on growing populations and (often expensive) infrastructure demands for more accurate and extensive records. However, trend detection is impeded by substantial limitation
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