The earthquake and tsunami
The magnitude-9.0 earthquake struck at 2:46 pm. (The early estimate of magnitude 8.9 was later revised upward.) The epicentre was located some 80 miles (130 km) east of the city of Sendai, Miyagi prefecture, and the focus occurred at a depth of 18.6 miles (about 30 km) below the floor of the western Pacific Ocean. The earthquake was caused by the rupture of a stretch of the subduction zone associated with the Japan Trench, which separates the Eurasian Plate from the subducting Pacific Plate. (Some geologists argue that this portion of the Eurasian Plate is actually a fragment of the North American Plate called the Okhotsk microplate.) A part of the subduction zone measuring approximately 190 miles (300 km) long by 95 miles (150 km) wide lurched as much as 164 feet (50 metres) to the east-southeast and thrust upward about 33 feet (10 metres). The March 11 temblor was felt as far away as Petropavlovsk-Kamchatsky, Russia; Kao-hsiung, Taiwan; and Beijing, China. It was preceded by several foreshocks, including a magnitude-7.2 event centred approximately 25 miles (40 km) away from the epicentre of the main quake. Hundreds of aftershocks, dozens of magnitude 6.0 or greater and two of magnitude 7.0 or greater, followed in the days and weeks after the main quake. (Nearly two years later, on December 7, 2012, a magnitude-7.3 tremor originated from the same plate boundary region. The quake caused no injuries and little damage.) The March 11, 2011, earthquake was the strongest to strike the region since the beginning of record keeping in the late 19th century, and it is considered one of the most powerful earthquakes ever recorded. It was later reported that a satellite orbiting at the outer edge of Earth’s atmosphere that day had detected infrasonics (very low-frequency sound waves) from the quake.
The sudden horizontal and vertical thrusting of the Pacific Plate, which has been slowly advancing under the Eurasian Plate near Japan, displaced the water above and spawned a series of highly destructive tsunami waves. A wave measuring some 33 feet high inundated the coast and flooded parts of the city of Sendai, including its airport and the surrounding countryside. According to some reports, one wave penetrated some 6 miles (10 km) inland after causing the Natori River, which separates Sendai from the city of Natori to the south, to overflow. Damaging tsunami waves struck the coasts of Iwate prefecture, just north of Miyagi prefecture, and Fukushima, Ibaraki, and Chiba, the prefectures extending along the Pacific coast south of Miyagi. In addition to Sendai, other communities hard-hit by the tsunami included Kamaishi and Miyako in Iwate; Ishinomaki, Kesennuma, and Shiogama in Miyagi; and Kitaibaraki and Hitachinaka in Ibaraki. As the floodwaters retreated back to the sea, they carried with them enormous quantities of debris, as well as thousands of victims caught in the deluge. Large stretches of land were left submerged under seawater, particularly in lower-lying areas.
The earthquake triggered tsunami warnings throughout the Pacific basin. The tsunami raced outward from the epicentre at speeds that approached about 500 miles (800 km) per hour. It generated waves 11 to 12 feet (3.3 to 3.6 metres) high along the coasts of Kauai and Hawaii in the Hawaiian Islands chain and 5-foot (1.5-metre) waves along the island of Shemya in the Aleutian Islands chain. Several hours later 9-foot (2.7-metre) tsunami waves struck the coasts of California and Oregon in North America. Finally, some 18 hours after the quake, waves roughly 1 foot (0.3 metre) high reached the coast of Antarctica and caused a portion of the Sulzberger Ice Shelf to break off its outer edge.
As a result, today more than 80,000 residents remain evacuated across the country, with no immediate prospect of being able to return to their abandoned homes and businesses.
The impact on the local economy has been no less harsh, with local industries, farm produce and tourism all strongly affected by associations of the name Fukushima with “nuclear contamination”.
Faced with a litany of problems, challenges and delays, Tokyo Electric Power Co, operators of the nuclear plant, have spent months working to bring it into a state of cold shutdown and claim to have at last succeeded.
Achieving cold shutdown may mark an important milestone in the recovery process, however, it will not mean that Japan’s problems are over: it will simply mark the next chapter of a painfully long recovery process for the nation.
Removal of the fuel from the reactors could take another ten years, according to expert estimates, while a full decommissioning profess could also last several decades.
Meanwhile, residents will not automatically be allowed to return, as the region has been earmarked for a major clean-up, although the government recently confirmed that this may not be able to commence until March next year at the earliest.
In addition to the physical clean up of the area – which will involve painstaking industrial cleansing of all buildings and removal of topsoil – there are continued concerns in relation to food safety across the country.
While Japanese food produce was once synonymous with safety and high quality production, a string of food safety scares – from green tea and beef to rice and even baby milk formula – have resulted in a growing sense of distrust among the public for government contamination safety testing.
The next steps for the government? First, they must continue to find the funds to finance the clean up, the reconstruction, the financial support for displaced residents, the health testing of children and the compensation payments for all those affected.
But another big challenge that lies ahead in 2012 is the government’s stance in relation to nuclear power. Although faced with a growing public backlash against all things nuclear, the nation’s 54 reactors are already slowly making a comeback.
Last month (NOV), the utilisation ratio of the nation’s reactors rebounded to more than 20 per cent for the first time since the disaster, with a total of ten reactors back online.
Private companies, however, are increasingly tapping into the energy backlash, with a growing number of projects exploring alternative sources such as solar, wind and geothermal – all of which are likely to become increasingly visible in Japan after next year as a growing number of new high-tech eco-communities are reconstructed from the rubble of the March 11 disaster.