FRI MAR 11, 2011 2:46 PM JST. SENDAI, MIYAGI PREF. Latent energy has been accumulating in the Japan Trench east of Sendai since 1933, in geologic time a scant 78 years. Tectonic movement is first detected by seismometers at 14:45 JST, triggering an early warning system that alerts citizens to an impending earthquake. Approximately one minute later, Japan’s largest and most populous island of Honshu begins shaking.
During the next several minutes, the torn fissure at the epicenter cascades into a series of ruptures rippling north and south along its fault line, situated under the Pacific Ocean, 130 kilometers east of the city of Sendai. The earth’s mantle grinds laterally over itself, east and west, as much as twenty meters, along the zone of subduction; vertical thrust is estimated to be as much as 30-40 meters.
A ten-centimeter drop in ocean-wave height is instantaneously measured at the nearest coastal station in Kamaishi. Two minutes later a ten-centimeter rise in ocean wave height is measured at Ishinomaki, one hundred kilometers to the south. Like a bathtub that is disturbed by a fallen object, these instantaneous changes in surface elevation, measured far away along the rim, are only a precursor to what is set in motion, ripples on sea skin, a faint clue to the massive sub-surface displacement that has begun its journey. The Japan Meteorological Agency, detecting the jolt, with the aid of a computer model, determines that a major tsunami of up to three meters in Iwate and Fukushima prefectures, and of up to six meters in Miyagi prefecture, is likely to occur as a result of the upheaval. It broadcasts an official tsunami warning to residents along the Tōhoku Coast.
FRI MAR 11, 2:54 PM. KESENNUMA, MIYAGI PREF. An offshore GPS buoy east of Kesennuma is the first instrument to detect the approaching tsunami. It measures six meters in height. The Japan Meteorological Agency updates its tsunami warning for the Tōhoku Coast, first issued at 2:49 p.m., revising the impending wave’s expected height upwards, to as high as ten meters.
FRI MAR 11, 3:15 PM. ŌFUNATO, IWATE PREF. The tsunami comes ashore at this fishing port of 42,000 people. It is measured at 3.2 meters in height, but – due to the funnel shape of Ōfunato’s bay and the amplifying effect of the shallow ocean floor – the wave reaches a shoreline elevation of 23.6 meters.
Over the next several minutes, from 3:15 to 3:21, the tsunami arrives up and down the Tōhoku coastline, alternately crashing into remote rocky headlands, or funneling-amplifying into populated village-lined bays. Up and down the Tōhoku coast, twenty cities each confirm casualties in excess of one hundred.
Hardest hit is Miyagi prefecture: Iwanuma (178), Tagajō (186), Watari (251), Onagawa (473), Minami-sanriku (514), Sendai (683), Natori (901), Kesennuma (930), Higashi-matsushima (1031), Ishinomaki (2964).
To the north, in Iwate prefecture: Ōfunato (321), Miyako (412), Yamada (566), Ōtsuchi (765), Kamaishi (837), Rikuzentakata (1490).
To the south, in Fukushima prefecture: Iwaki (303), Soma (424), Minami-soma (504).
Twenty-three other cities as far north as Aomori and Hokkaidō prefectures, and as far south as Ibaraki and Chiba prefectures, count casualties, though less than one hundred each. Just as in Ōfunato, the wave totally destroys buildings, boats, ports and infrastructure.
In addition to the confirmed death of 15,000 people, there are 8,000 people swept out to sea.
FRI MAR 11, 9:00 PM. FUTABA, FUKUSHIMA PREF. Within two hours of the tsunami’s arrival, the government declares a nuclear emergency, and three hours later at 9 p.m., it issues a general evacuation order for citizens living within three kilometers of Fukushima Daiichi. The Fukushima Daiichi complex has six reactors, each housed in separate containment buildings situated close to each other. The evacuation order includes farmers and rural residents living near the complex, also the citizens of the nearby towns of Futaba and Ōkuma.
Futaba, a coastal town of 7,248 residents, is reeling from near-complete devastation. A municipal official states that 90% of the town’s houses have been washed away by the tsunami. At this time it is unknown how many have been killed or swept out to sea. The temperature is close to the freezing point, rain is falling, darkness has been upon the scene for three hours, and there is nothing to do but leave as ordered. The unaccounted-for victims will be left uninterred: a death without dignity. There will be no returning.
Ōkuma, a town of 11,159 residents, situated a few kilometers inland from Futaba, has not been damaged by the tsunami. Although portions of Ōkuma are within the three-kilometer radius, other portions of it – including the hospital – are just outside the nuclear evacuation zone and become a temporary refuge for the evacuees.
FRI MAR 11, 3:14 AM HAST. KAHULUI, HAWAII. After traveling 6018 kilometers, the tsunami reaches Kahului on the island of Maui. The tsunami arrives seven hours and forty minutes after the earthquake; it measures two meters in height.
FRI MAR 11, 7:34 AM PST. CRESCENT CITY, CALIF. After traveling 7542 kilometers, the tsunami reaches the northern California coastal community of Crescent City. The tsunami arrives nine hours and forty-eight minutes after the earthquake; it measures two and one-half meters in height.