04/09/2018
Storm Surge
Under the influence of Typhoon Jebi, Kansai International Airport in Japan, which opened just 24 years ago (on 4/9/1994), is temporarily shut down today.
The runway of the airport is flooded with seawater, and the connecting bridge between the airport island and the mainland Japan has become inaccessible due to an accidental hit of a tanker. (You may refer to the photo of the post as well as that in the comment section.)
As mentioned, Kansai Airport was built on an artificial island. The typhoon was very close to the island and brought a severe storm surge which flooded the airport.
So what is a storm surge? Storm surge is a coastal flood or tsunami-like phenomenon of rising water caused by low-pressure weather system like typhoons. The intensity of a storm surge is mainly affected by the orientation of the water body in related to the storm path, as well as the timing (which is related to astronomical daily tides). If a severe storm surge is cumulated from the daily high tide, a severe flood will occur very likely.
In the case of Jebi, the storm surge is mainly caused by the typhoon itself, as today (4/9/2018) is the 25th day of a lunar month (where high tides will usually occur on the 1st and 15th day of a lunar month). Thus, the flooding is less intense.
Nonetheless, the high tide of the typhoon makes the tide record today more than 2 meters higher of the normal level, which has exceeded 3 meters from the sea level.
From past experiences, most of the casualties from a tropical cyclone come from neither heavy rain or strong wind. Storm surge has always been the “real killer”.
Let’s use Hato, the typhoon that greatly hit Zhujiang Delta region last year, as an example. Most of the casualties were because of the storm surge cumulated from the high astronomical tide.
In Hong Kong, an underground car park was flooded with seawater in Heng Fa Chuen. This caused a great loss to the car owners. Lower grounds like Tai O were also flooded.
In Macau, the storm surge flooded most of the old areas of Macau Peninsula. Ten people were killed.
Whenever a tropical cyclone approaches, be aware of this “killer” — storm surge.
Books related to weather (meteorology) can be found in the library shelves with Class Number 551.
The image was obtained from NHK.