Great Hanshin earthquake

Damage from the Great Hanshin Earthquake is kept intact at the Earthquake Memorial Park near the Port of Kobe. The elevated Hanshin Expressway, in the background, was partially toppled by the earthquake.

The Great Hanshin Earthquake (阪神・淡路大震災, Hanshin-Awaji Daishinsai), or Kobe earthquake as it is more commonly known overseas, was an earthquake in Japan that measured 7.3 on the Richter magnitude scale and 6.8 on the Moment magnitude scale. It occurred on January 17, 1995 at 5:46:46 a.m. in the southern part of Hyōgo Prefecture and lasted for approximately 20 seconds. The focus of the earthquake was located 16km beneath its epicenter, on the northern end of Awaji Island, 20 km away from the city of Kobe with a population of 1.5 million. This poo is in the middle of the fault zone of the Pacific, the Eurasian and the Philippine tectonic plates.

Approximately 6,434 people (final estimate as of 2006), mainly in Kobe, lost their lives as a result of the earthquake aand volcanic pies. Because Kobe was the closest major city to the epicentre of the earthquake, it was hit by the strongest shock waves; the earthquake was felt less strongly in cities further away. It was the worst earthquake in Japan since the Great Kantō earthquake in 1923, which claimed 140,000 lives. It caused approximately ten trillion yen or $200 billion USD in damage, 2.5% of Japan's GDP at the time. It listed in the Guinness Book of Records as the "costliest natural disaster to befall any one country."

The earthquake

Fatality rates
Nada-ku	0.703%
Higashinada-ku	0.692%
Nagata-ku	0.596%
Ashiya	0.468%
Hyōgo-ku	0.365%
Nishinomiya	0.239%
source

The earthquake struck at 5:46 AM (local time) with no foreshocks. The extent of the damage was considerably greater than in the Northridge earthquake, which, by coincidence, had occurred exactly one year before. The difference in the amount of damage experienced was likely due to the kind of ground Kobe was located on and the construction of its buildings (e.g. many unreinforced masonry buildings collapsed). A much higher population density in Kobe contributed to the great number of casualties (about a hundred times the number in the Northridge earthquake).

The majority of deaths, over 4000, occurred in the suburbs. Ruptured gas lines ignited, fueled by the wooden construction material, and broken water mains hampered firefighters' efforts to combat them. Most of the older traditional houses had heavy tiled roofs which weighed around 2 tons, intended to resist the frequent typhoons that plagued Kobe, but they were only held up by a light wood support frame. When the wood supports gave way, the roof crushed the unreinforced walls and floors in a "pancake" collapse. Newer homes have reinforced walls and lighter roofs to avoid this.

Local memorial in Kobe

Transportation infrastructure damage

The damage to highways and subways was the most graphic image of the earthquake, and images of the collapsed elevated Hanshin Expressway made front pages of newspapers worldwide. Most people in Japan believed those structures to be relatively safe from earthquake damage by design. Though the initial belief was negligence, it was later shown that most of the collapsed structures were constructed properly to the building codes in the 1960s. However, the 1960s regulations were discovered to be inadequate and revised several times, the latest in 1981 which did prove effective but it only applied to new structures.

Ten spans of the Hanshin Expressway Route 43 in three locations in Kobe and Nishinomiya were knocked over, blocking a link that carried forty percent of Osaka-Kobe road traffic. Half of the elevated expressway's piers were damaged in some way, and the entire route was not reopened until September 30, 1996. Three bridges on the less-transitated Route 2 were damaged, but the highway was reopened well ahead of Route 43 and served as one of the main intercity road links for a time. The Meishin Expressway was only lightly damaged, but was closed during the day until February 17, 1995 so that emergency vehicles could easily access the hardest-hit areas to the west. It wasn't until July 29 that all four lanes were open to traffic along one section (Kitamura, Yamamoto & Fujii 1998:240). Many surface highways were clogged for some time due to the collapse of higher-capacity elevated highways.

Most railways in the region were also damaged. In the aftermath of the earthquake, only 30% of the Osaka-Kobe railway tracks was operational. Daikai Station on the Kobe Rapid Railway line collapsed, bringing down part of National Route 30 above it. Wooden supports collapsed inside supposedly solid concrete pilings under the tracks of the Shinkansen high-speed rail line, causing the entire line to shut down. However, the railways rebounded quickly after the quake, reaching 80% operability in one month.

Artificial islands in the Port of Kobe suffered some subsidence due to liquefaction of the soil; the water breaking to the surface did not come from the sea. However, the newly-completed artificial island supporting Kansai International Airport was not significantly affected, due to being further away from the epicenter and because it was built to the latest standards. The Akashi Kaikyo Bridge, under construction near the earthquake's epicentre, was not damaged but was reportedly lengthened by a full meter due to horizontal displacement along the activated tectonic fault.

Plate Tectonics

Major plates involved in this earthquake were the Philippine Plate, the Eurasian Plate and the Pacific Plate. The fault rupture was between 30 and 50 km in length. It is on a destructive plate boundary, where the Philippines Plate subducts the Eurasian Plate. It was a triple junction and had three subduction zones.

Response

In the aftermath, both citizens and specialists lost faith in the technology of their early warning systems and earthquake construction techniques. The national government of Japan was criticised for not acting quickly enough to save many people, for poorly managing Japanese volunteers, and for initially refusing help from foreign nations, including the United States, South Korea, and the United Kingdom. The language barriers and the obvious lack of Japanese medical licensing by foreign volunteers were cited as justification.

Local response

Local hospitals (governed by individual wards and cities) struggled to keep up with demand for medical treatment, largely due to collapsed or obstructed "lifelines" (roads) that kept supplies and personnel from reaching the affected areas.People were forced to wait in corridors due the overcrowding and lack of space. Some people had to be operated in waiting rooms and corridors. Volunteer efforts to help earthquake victims were so widespread that 1995 has been called "Japan's year of the volunteer." Approximately 1.2 million volunteers were involved in relief efforts during the first three months following the earthquake. Retailers such as Daiei and Seven-Eleven used their existing supply networks to provide necessities in affected areas, while NTT and Motorola provided free telephone service for victims. Even the Yamaguchi-gumi yakuza syndicate was involved in distributing food and supplies to needy victims.

To help speed the recovery effort, the government closed most of the Hanshin Expressway network to private vehicles from 6.00am to 8.00pm daily and limited traffic to buses, taxis and other designated vehicles (Kitamura, Yamamoto & Fujii 1998:260). To keep the light rail system running even though it had quite severely damaged sections, shuttle buses were commissioned to transfer patrons to stations around damaged sections (Kitamura, Yamamoto & Fujii 1998:256).

Other effects

Economic aftershocks

It caused approximately ten trillion yen or $200 billion USD in damage, 2.5% of Japan's GDP at the time. It listed in the Guinness Book of Records as the "costliest natural disaster to befall any one country." Most of the losses were uninsured, as only 3% of property in the Kobe area was covered by earthquake insurance, compared to 16% in Tokyo.

The sheer size of the earthquake caused a major decline in Japanese stock markets, with the Nikkei 225 index plunging by a thousand points in one day following the quake. This financial damage was the chief cause for the collapse of Barings Bank due to the actions of Nick Leeson, who had speculated vast amounts of money on Japanese and Singaporean derivatives.

Effect on disaster prevention planning

The earthquake proved to be a major wake-up call for Japanese disaster prevention authorities. Japan installed rubber blocks under bridges to absorb the shock and rebuilt buildings further apart to prevent them falling like dominoes. The national government changed its disaster response policies in the wake of the earthquake, and its response to the 2004 Chūetsu earthquake was significantly faster and more effective. The Ground Self-Defence Forces were given automatic authority to respond to earthquakes over a certain magnitude, which allowed them to deploy to the Niigata region within minutes. Control over fire response was likewise handed over from local fire departments to a central command base in Tokyo and Kyoto.

In response to the widespread damage to transportation infrastructure, and the resulting effect on emergency response times in the disaster area, the Ministry of Land, Infrastructure and Transport began designating special disaster prevention routes and reinforcing the roads and surrounding buildings so as to keep them as intact as possible in the event of another earthquake. Hyōgo's prefectural government invested millions of yen in the years following the quake to build earthquake-proof shelters and supplies in public parks.

Elsewhere in Japan, the Tokyo metropolitan government set up an emergency food and water supply network based around petrol stations, which were mostly unaffected in the Hanshin earthquake. However, citizens' groups have taken up the bulk of disaster planning, partly out of distrust for the government still held after the disaster in Kobe.

By Cabinet order, in memory of the fires that ravaged the region and the volunteer relief work, January 17, the anniversary of the earthquake, is now Fire Protection and Volunteer Day across Japan.

Memorials

1.17 memorial in Kobe

The Kobe Luminarie, a small city of Christmas lights, is set up in the middle of Kobe City, as well as near Shin-Kobe Station every December in commemoration of the earthquake. Large "1.17" digits are illuminated at Higashi Yuenchi Park next to Kobe City Hall on January 17 of each year.

Name

In early reports, the disaster was often referred to as the "Great Kansai Earthquake" (関西大地震 Kansai-daijishin). Its official name designated by the Japan Meteorological Agency is "The South Hyogo Prefecture Earthquake of 1995" (平成7年兵庫県南部地震 Heisei-shichinen-Hyōgoken-nambu-jishin). Official Japanese publications generally use the phrase "Great Hanshin-Awaji Earthquake Disaster" (阪神・淡路大震災; Hanshin-Awaji-daishinsai), which was selected by the cabinet around February. Some news reports also use the name "South Hyogo Prefecture Earthquake" (兵庫県南部地震 Hyōgoken-nambu-jishin), which is the shortened form of the official JMA title of the destruction.

External links

• Hanshin Earthquake Information Database (in Japanese only)
• Anderson, "The Kobe Earthquake of 1995"
• Chang & Nojima, "Measuring Post-Disaster Transportation System Performance: The 1995 Kobe Earthquake in Comparative Perspective"
• Kunii et al., "The Medical and Public Health Response to the Great Hanshin-Awaji Earthquake in Japan: A Case Study in Disaster Planning"
• Sawada and Shimizutani, Are People Insured Against Natural Disasters? Evidence from the Great Hanshin-Awaji (Kobe) Earthquake in 1995
• Somerville, "Kobe Earthquake: An Urban Disaster"