It may sound strange to talk about a magnitude-9.0 quake and tsunami as something that's mystifyingly small. But the UNUSUAL scenario that played out on March 11, 2011, shows how much we still have to learn about how earthquakes work. Moreover, it shows that scientists may not fully understand the mechanism of seismic shocks for the foreseeable future. "The most obvious lesson learned is to plan for the unexpected."
Scientists have long known that the Japan Trench, where the oceanic Pacific Plate dives beneath the continental Okhotsk Plate, was seismically active. It's part of the "Pacific Ring of Fire" that runs like a horseshoe around the ocean's edge. But scientists and engineers thought the trench wasn't capable of generating earthquakes that big — and so they designed structures such as seawalls and nuclear power plants to fit what they saw as prudent probabilities. So what happens when the big, unexpected event happens? Seawalls are breached. Airports are wrecked. Towns are wiped out. Nuclear plants are swamped. "They believed their risk models, and they shouldn't have."
It's tempting to think that Japan has had its "once-in-a-millennium" seismic shock, and that people can relax for the next 999 years. After all, last year's earthquake was big enough to shift Honshu, Japan's main island, as much as 13 feet to the east. It also gave Earth's axis a 6.5-inch readustment and shortened the length of the day by 1.8 microseconds. But the geophysical shifts raise additional questions. Here's a potential biggie: Honshu has been subsiding for the past century, and the earthquake just added to the subsidence. That was unexpected, because seismologists assumed that an earthquake would release the crustal strain and result in an uplift. "We know we can't continue to go down at these rates forever, or Honshu would just disappear in a million years or so." Will the island slowly stop sinking and then start rising again? Or will the strain continue to build until another big earthquake releases it? "We don't know the answer to that, but it's a pretty important question."
Last May, a team of researchers analyzed the seismic data from before and after the quake, and found that significant slip was experienced along a 150-mile length of the Japan Trench fault — which is about half the length that would have been expected for a magnitude-9.0 event. They also reported that the conditions they saw in the area of the quake's epicenter before March 11, 2011, still exist today in the area to the south, known as the Ibaraki region. "It is important to note that we are not predicting an earthquake here. However, we do not have data on the area, and therefore should focus attention there, given its proximity to Tokyo." Just this week, Japanese researchers reported that Tokyo could be more vulnerable to a magnitude-7 quake in northern Tokyo Bay than they previously thought, and they said older structures should be reinforced to meet more stringent standards. "If a building narrowly fulfills the law's standards, its quake resistance is not high."
It only makes sense to expect further surprises from seismological studies, including some nasty ones. "My experience as a human is that there's a good chance there's something we didn't know. ... It keeps coming up over and over again that there are major holes in our understanding of the system."
for the light, for your life, for your strength.
Give thanks for your food and for the joy of living.
If you see no reason to give thanks,
the fault lies in yourself.**
LARGEST QUAKES -
This morning -
None 5.0 or higher.
5.0 SOUTHERN SUMATRA, INDONESIA
5.0 OFF EAST COAST OF HONSHU, JAPAN
5.0 EAST OF KURIL ISLANDS
5.8 ALASKA PENINSULA
5.3 TARAPACA, CHILE
5.2 OFF EAST COAST OF HONSHU, JAPAN
5.3 NEAR EAST COAST OF HONSHU, JAPAN
7 Strange Ways the Japan Quake Shook the World - Not only did the twin events cause widespread damage along Japan's coast but they also triggered effects across the globe, from the surface to high up in the atmosphere.
7 – Cracks in the seafloor
The earthquake ruptured below the seafloor off the coast of the Tohoku region, ripping open cracks along the ocean bottom. Submersibles spied these cracks, which measured around 3 to 6 feet (around 1 to 3meters) across, in the months after the earthquake.
6 – Smaller quakes triggered worldwide
The massive 9.0 temblor shook large sections of Japan and is still setting off aftershocks in the area. But the shaking wasn't limited to the immediate region, some scientists think. There is evidence that the quake set off microquakes and tremors around the globe, mostly in places already known for their seismic activity such as Taiwan, Alaska and central California. These events likely didn't exceed a magnitude of 3.0. However, some of the quakes occurred in low-activity areas, such as central Nebraska, central Arkansas and near Beijing. Tremors were even detected in Cuba. Scientists hope that linking these seismic events can help them better understand the inner workings of earthquakes.
5 – Antarctic ice stream sped up
Thousands of miles away from Japan, the seismic waves of the Tohoku earthquake appeared to temporarily speed up the flow of the Whillans glacier. Glaciers are essentially rivers of ice that slowly flow, in the case of Antarctica, from the interior of the continent out to sea. The increased pace of the ice stream was detected by GPS stations located on the ice.
4 - Antarctic iceberg broken
The earthquake and its resulting tsunami were so powerful and far-reaching that they also broke off huge icebergs from Antarctica's Sulzberger Ice Shelf. (An ice shelf is the part of a glacier that floats atop the sea.) Satellite images detected the tsunami waves breaking off chunks of ice some 18 hours after the earthquake.
3 – Atmosphere was rattled
The massive earthquake not only shook the earth, but also rattled the atmosphere. Research had indicated that the surface motions and tsunamis that earthquakes generate can also trigger waves in the atmosphere, and the Japan earthquake generated THE LARGEST SUCH DISTURBANCES YET SEEN, creating ripples in electrically charged particles reaching nearly 220 miles (350 kilometers) above the Earth.
2 – Gravity altered
The earthquake was so powerful that it altered the pull of gravity under the area affected by the quake, as detected by the Gravity Recovery and Climate Experiment satellites. The quake slightly thinned the crust, causes a slight reduction in the local gravity field.
1 – Earth's day shortened
An analysis conducted just days after the earthquake struck found that the temblor accelerated Earth's spin, shortening the length of the 24-hour day by 1.8 microseconds. A microsecond is a millionth of a second. The planet's rotation sped up because the earthquake shifted the distribution of Earth's mass.
Japan earthquake and tsunami anniversary: one year on, debris still piled high, after public hysteria that the rubbish may have been tainted by the radioactive clouds from the Fukishima Daiichi nuclear plant.
Japan has wasted the entire year since the giant earthquake and tsunami destroyed its North East coast, the Japanese Red Cross said, as more than a quarter of a million survivors face up to five more years in temporary shelters. 478 bodies remain unidentified one year on.
Colombian volcano waking up - The Nevado del Ruiz volcano, whose eruption 26 years ago killed around 25,000 people, is showing signs of activity after nearly 20 years laying dormant.
Alert level raised for Alaska's Iliamna volcano - An alert level for the possible eruption of the volcano southwest of Anchorage was raised by volcanologists Friday afternoon. The Alaska Volcano Observatory raised Iliamna Volcano's alert level to advisory. The "advisory" warning of yellow means that the volcano is experiencing unusual activity, but hasn't explicitly erupted. Kanaga volcano in the Aleutians had a minor eruption back in February that launched a small ash cloud and prompted a similar advisory.
This week there was also a small eruption at Cleveland Volcano, located about 940 miles southwest of Anchorage.
Russia - Bezymianny volcano erupts again. Friday saw a new eruption of the Bezymianny volcano on the KamchatkaPeninsula in the Russian Far East. Earlier in the day, the volcano spewed ash up to 8 kilometers high.
TROPICAL STORMS -
In the Indian Ocean -
Tropical cyclone 16s (Koji) was located approximately 930 nm south-southeast of Diego Garcia.
Australia - Cyclone Lua likely to form near Pilbara coast. It is possible that it will develop into a tropical cyclone today, but it is more likely to reach tropical cyclone intensity during the week. The risk of tropical cyclone development for this system is currently rated
as 'high' (greater than 50%).
At Least 111 Killed in Madagascar Tropical Storm - The moderate tropical storm Irina, which swept through the northeast of Madagascar on Feb. 26 and docked the southwest coast of the island country until March 2, earlier was reported to have killed 76 people and injured 15.
SEVERE RAIN STORMS, FLOODING, LANDSLIDES -
Hawaii Pummeled By 'Severe Weather' As La Nina Turns To El Nino - Meteorologists are taking note of the extreme weather conditions that continue to cloud Hawaii's normally sunny climatic disposition. “Feet of rain” has fallen in some areas. Hanalei, Hawaii, received 35.97 inches of rain in just over two days. Multiple landslides have blocked highways throughout the state. Violent thunderstorms produced hail with diameters up to 2 inches in Kailua and Kaneohe. Not only is it HIGHLY UNUSUAL for hail to fall over Hawaii, but some stones that measured as large as three inches are likely record-breaking. “What is going on in Hawaii is a symptom of the change from La Niña to El Niño coming on."
HEAVY SNOW / EXTREME COLD -
Afghanistan - At least 145 people are missing and "presumed dead" after an avalanche hit a village in Afghanistan's northeastern Badakhshan province last week. Afghan officials had earlier Saturday put the death toll from the March 4 series of avalanches in Badakhshan's Shekay district at 56. The UN said an avalanche in the area claimed 50 lives and warned of severe flooding over coming weeks due to melting snow. Afghanistan's harshest winter in 15 years has claimed scores of lives, with the avalanches taking the toll to more than 90 in Badakhsh alone. "Access to Dispay village is possible only by road from neighboring Tajikistan but has been severely hampered by snow-blocked roads. Helicopter access is not possible as there is a high risk of triggering further avalanches."
EXTREME HEAT & DROUGHT / WILDFIRES / CLIMATE CHANGE -
Great Lakes winter ice cover has decreased 71 percent since 1973 - The average amount of ice covering the Great Lakes declined 71 percent over the past 40 winters, with Lake Superior ice down 79 percent. “There was a significant downward trend in ice coverage from 1973 to the present for all of the lakes." Researchers used Coast Guard reports and satellite photographs taken from 1973 to 2010 to determine the ice coverage of all the lakes, with Lake Ontario ice dropping 88 percent while ice in Lake St. Clair (between Lake Huron and Lake Erie) diminished just 37 percent.
The findings don’t include the current winter, but 2011-12 will only speed up the decline. Only about 5 percent of the Great Lakes surface froze over this winter, the least since satellite photos first were taken from space. That compares to winters that saw as much as 94 percent ice coverage, such as in 1979. It’s also way down from the average winter of about 40 percent coverage. The results won’t be a surprise to Northlanders who have gazed out all winter over open water on the western tip of Lake Superior, where almost no ice has formed. Even in protected Chequamegon Bay, which usually freezes enough for trucks to drive on, strong ice never formed this winter, forcing the Madeline Island ferry to operate all season. That’s only the second time that’s ever happened. The results echo other studies that show much higher surface water temperatures on Lake Superior in recent years and far fewer days of ice cover.
Diminished ice can speed up wintertime evaporation, reducing water levels. It also may lead to increased and earlier algae blooms, which can damage water quality, and may accelerate erosion by exposing more shoreline to waves. The decline in ice cover probably is due to several factors, including cyclical climate patterns like El Niño and La Niña (unusually high temperatures and unusually low temperatures, respectively, in the Pacific), changes in the Arctic Oscillation and broader climate change.