April 1781 Tsunami: Kaohsiung, Taiwan

Ref #8575:

Yang (1987): "Weather was fine, suddenly sea roared with wave of >30 m, and ebbed. Taiwan Strait earthquake, tsunami lasted 1-8 hrs, >50000 people died." Yang, W. T.: Tsunami and Pacific tsunami warning system, Marine Forecasts, Year 1987(S1), 68-76, 1987.

Yu (1994) and Mak and Chan (2007): Weather was fine, suddenly sea roared with wave of >30 m, and ebbed. Houses submerged, one woman died. Y, M. S.: Destructive Earthquake Tsunamis in the Ming and Ching Eras, Meteorological Bulletin, 40(1), 37-46, 1994. Mak and Chan (2007): Mak, S. and Chan, L. S.: Historical tsunamis in South China, Nat. Hazards, 43(1), 147-164, 2007.

Yu (1994) has the tsunami impacting Pingtung (Taiwan) and the source as an earthquake magnitude 6.4, (possible) distant earthquake.

Mak and Chan (2007) have the tsunami impacting Kaohsiung (Taiwan), source: lat 24 / long 121.

The event in the database that best illustrates the inconsistency in reporting death tolls is the 1781 event in SW Taiwan. The reported number of fatalities associated with this event that occurred between April and June 1781 is inconsistent between all entries. Three out of four entries that record this event provide details of a tsunami. The death of one woman was reported in 2 entries with reference made to "Taiwan interview catalogue" (Chen et al., 1830). In contrast, Yang (1987) recorded >50 000 deaths associated with a tsunami caused by a Taiwan Strait earthquake in May. The death toll reported for this event appears erroneous since it is not cited in the detailed publications of Soloviev and Go (1974), and Zhou and Adam (1986). However, the inclusion of the 1781 tsunami-like event into the work of Yang (1987) has been generally accepted and this "deadly" tsunami report is now widely quoted among Chinese literatures.

The Yang (1987) record of the 1781 April-June event is possibly the best example of how erroneous reporting can arise when including information from previous publications. Yang outlines many detail including a "tsunami" that "lasted for 1-8 h" from which "over 50000 people died" at "Taiwan and Taiwan Strait". The descriptions are similar to those for the 22 May 1782 event recorded for Taiwan by Iida et al. (1967) and Soloviev and Go (1974). Therefore, it appears very likely that Yang (1987) mixed details of the 1782 event with that of 1781 when composing the tsunami event list.

Ref #10200:

sea-surge occurred somewhere between 24 April 1781 and 21 June 1781, at Qieteng Bay, Taiwan (near the current Dapeng Bay, Donggang, approximately 30 km southeast to Kaohsiung). The flood was reported to last for a few quarters, which is a typical period of a tsunami […] this event is sufficient to be validated as tsunami. The weather was reported to be fine, eliminating the possibility of a storm surge. No earthquake was reported in the region in this period, suggesting that the tsunami was probably not tectonic in origin. The run-up was reported both quantitatively (tens of zhangs) and qualitatively (about a bamboo high). One woman was reported to be drowned. The reporter's name was also recorded, which was not a common practice in local historiographies, giving support to the reliability of the report. The event was not recorded in the official dynastic record, possibly because the damage was minor. This event is the only tsunami with explicit damage (one life and several huts) in South China in the history.

Ref #12391:

Around 4th to 5th month, 46th Qianlong year (1781), weather was fine. Suddenly sea roared like thunder, giant wave appeared. Water rose for tens of zhang high (1 zhang is approx. 1-1/3 m). Villagers nearby were submerged, they climbed upwards, expecting to die[...]It was heard that one woman was drown. Fishmen sailed on top of bamboos on raft, watch their homes submerged far from.