Japan Case Study Notes

Japan

Q1 Tectonics

The meeting of four tectonic plates à

Destructive plates create Fold Mountains to form the series of islands.

Mt Kirishima = explosive composite volcano. 10% of the most active volcanoes are in Japan.

Japan is a part of the Pacific ring of fire which follows the Western boundary of the Pacific plate and here occur around 90% of all earthquakes.

Pacific plate sub ducts beneath the North American and Philippine plate to create the Japan Trench. ß Most volcanoes found along this point.

On average, the Pacific Plate is moving west at about 9cms per year, and the movement has produced major earthquakes in the past — nine earthquakes of magnitude 7 or greater since 1973.

http://www.ouramazingplanet.com/1048-japan-tectonics-explosive-geology-ring-of-fire-110314.html

Q2 Landscape

Japan is approximately 375,000km², consists of 2,456 islands in total.

Japan is located in Eastern Asia. It’s a series of islands east of the Korean peninsula.

The Japanese islands are the summits of mountain ridges uplifted near the outer edge of the continental shelf therefore 73% of Japan is mountainous (high relief) with a mountain range running through each of the main islands. (e.g. the Japanese Alps) The highest point on the island is Mount Fuji at around 12,400ft. ß High risk of landslides

There are a few plains and river basins many of which are near the coast and heavily populated. Areas around Tokyo for example are reclaimed (popular for buildings and harbours around the city). None of the populated plains or mountain basins are extensive in area. The largest, the Kanto Plain, where Tokyo is situated, covers only 13,000 square kilometres.

With expanding population there have been challenges with land space leading to human modifications:

·         Land extensions (reclaimed land, marshes)

·         Artificial islands e.g. Port Island in Kobe

·         Reclaimed land from river deltas, drainage

·         Carved/degraded mountainsides

Rivers no longer than 400kms, often small and steep river Shinano is the longest.

Islands difficult to get inland, rivers fast flowing and violent, roads rare therefore rural populations hard to reach in emergencies.

Q3 People

 Violent earthquakes, volcanic eruptions etc. high death toll but well prepared due to MEDC status and funds. See individual events for specific examples à

Q4 Management

Scientists carry out seismic monitoring of plates to provide warnings with sirens, education drills and emergency packs etc. ß However, the warning for the recent tsunami in 2011 was sent out only 15minutes ahead of the tsunami.

After 1995 in Kobe, the Japanese government created new laws to increase the standard of building regulations to withstand earthquakes.

Tectonic events

Kobe 1995  

An earthquake measuring 7.2 on the Richter scale in January 1995 of which the epicentre found beneath Kobe City ß significant damage was incurred because the epicentre was shallow in the crust hence the quake reached the surface quicker with less energy lost.

ß Caused by a slip fault between the pacific plate sub ducting beneath the Philippine plate.

Effects:

·         Pancaked houses (flattened) leaving 300,000 people homeless.

·         Crashing of gas pipes and electricity. ß +150 Fires in the city leading to over 1,000 deaths.

·         Hanshin Highway collapsed. ß Early morning low impact but cut of transport routes. Double storey highways, collapse also damaged surrounding buildings.

·         Liquefaction weakened building structures cracked roads.

·         5,500 killed in total.

Emergency resources were sent out but many did not reach those who needed it because of transportation problems.

‘Robo-rat’ was developed after the quake to find people in the rubble safely.