A synthesis of the 2013 Typhoon Haiyan storm surge, the deposits and the post event state of the coast.
Abstract
Typhoon Haiyan in 2013 was an extremely intense and fast moving typhoon. The typhoon claimed more than 6000 lives, caused widespread damage, and affected more than 16 million people along its path in central Philippines. Overwash associated with the 5 to 8 m storm surge of Typhoon Haiyan also left behind a variety of geomorphic and sedimentological imprints, which provide a valuable dataset for modern storm deposits in different landform settings. Here we present a synthesis of the geological and geomorphological record from sites that span clastic, mixed clastic-carbonate, and non-clastic carbonate coasts affected by contrasting surge mechanisms. On the sheltered clastic coast where overwash was dominated by wind-induced setup surge, the overwash sediments occur as a sand unit of no more than 20 cm near the shore, and then spread into sub-cm thin sandsheet that blanket pre-Haiyan soil surfaces up to 1.6 km inland. Thicker sections of the overwash sand exhibit sharp, depositional contacts, planar stratification, and generally coarsen upward and fine landward. On the mixed clastic-carbonate coast, the Typhoon Haiyan deposits are generally thin (<10cm), massive, poorly sorted, fine sand unit that contain carbonate material including foraminifera and mollusks fragments, and extend over 350 m inland. On the open carbonate coast that was affected by a wave-dominated setup surge, the overwash sediments include two distinct assemblages: carbonate boulders now occupying the reef flat surface, and a sand sheet that blanketed the coastal plain up to 300 m distance inland. Overall, Haiyan's overwash sediments exhibit characteristics that are consistent with other overwash sediments from comparably intense storm surges, but are also observed in recent tsunami deposits. Thus, although the Haiyan overwash sediments excellently represent a rare modern-day record of an extreme storm, the sediment signatures of Haiyan do share many of the characteristics of tsunami deposits suggesting caution when interpreting inundation events in the geologic record.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2017
- Bibcode:
- 2017AGUFMGC11D..06S
- Keywords:
-
- 1615 Biogeochemical cycles;
- processes;
- and modeling;
- GLOBAL CHANGE;
- 1824 Geomorphology: general;
- HYDROLOGY;
- 1895 Instruments and techniques: monitoring;
- HYDROLOGY;
- 4217 Coastal processes;
- OCEANOGRAPHY: GENERAL