LARGEST QUAKES -
This morning -
5.6 NEAR EAST COAST OF HONSHU, JAPAN
5.2 NEAR EAST COAST OF HONSHU, JAPAN
5.1 BANDA SEA
5.4 MINDORO, PHILIPPINES
5.5 HINDU KUSH REGION, AFGHANISTAN
5.1 OFF EAST COAST OF HONSHU, JAPAN
5.0 OFF EAST COAST OF HONSHU, JAPAN
5.2 OFF EAST COAST OF HONSHU, JAPAN
5.2 OFF EAST COAST OF HONSHU, JAPAN
5.0 NEAR EAST COAST OF HONSHU, JAPAN
5.1 OFF EAST COAST OF HONSHU, JAPAN
5.2 NEAR EAST COAST OF HONSHU, JAPAN
As far as 20km away from the Fukushima nuclear plant in Japan, radiation recorded at levels 1600 times higher than normal.
Does the Japan Quake Make a US Quake More Likely? - Seismically speaking, it's been a rough few months on the Pacific rim. On February 27, 2010, an 8.8-magnitude earthquake struck Chile. In September, two major quakes rocked New Zealand's South Island, and a 6.3 followed in February in Christchurch. Just a few weeks after that, the devastating 9.0 quake struck Japan, causing a tsunami and a nuclear crisis. These quakes occurred on three of the four "corners" of the notoriously jumpy Ring of Fire. The other corner? The West Coast of the United States. So does this series of earthquakes up the US's chances of the dreaded "Big One"? A Newsweek story from last week suggests that the answer is yes, since the earth is "like a great brass bell, which when struck by an enormous hammer blow on one side sets to vibrating and ringing from all over." Rogue seismologist Jim Berkland, who claims to be able to predict earthquakes based in part on tides and the moon, has also warned that a major US quake is imminent.
Seismologists agree that major quakes do have local ripple effects. In addition to aftershocks, which can contine for a few weeks after a quake the size of Japan's, earthquakes can also beget more earthquakes on other parts of the same plate, or even on nearby faults. When a quake occurs, stress is relieved in one area of a plate and transferred to other parts of that plate. "So, unhappily, we know that Port-au-Prince [Haiti] is at even greater risk than it was before the quake last year. And the recent earthquake in Christchurch [New Zealand] was probably 'triggered' by the one that occurred in September the year before."
How far can the transferred stress travel? There are increased levels of stress as far as 186 miles from the epicenter of the March 11 quake in Japan. The New Zealand earthquakes all occurred within a few hundred miles; they were probably connected. Similarly, the quake that struck the Indian Ocean and triggered a tsunami in 2004 likely triggered another series of quakes in Sumatra in 2007. Some scientists believe the stress transfer zones can extend even further. "The recent spurt of magnitude-8-plus earthquakes may be an extended aftershock sequence of the 2004 Sumatra earthquake." But seismologists aren't in agreement about this point, and the bottom line is that there's not enough data to say conclusively whether they're all related. And there's certainly no evidence that a quake can transfer stress across as great of a distance as that between Japan and the US. "That's too far for stress to act." Which is not to say that the Big One isn't imminent, or that we shouldn't take precautions. The West Coast straddles several fault lines."
Why can't we predict the next big quake? - Why can't seismologists predict earthquakes? It's a question and a frustration that understandably springs to mind in the aftermath of a tragedy like the one that continues to unfold in Japan. In the 1970s and 1980s (not exactly ancient times), leading scientists were quoted in the media expressing optimism that reliable, short-term prediction was just around the corner. Several decades later, the earthquake science community is older and wiser. We have learned, in short, that prediction is a tough nut to crack. To make the kind of accurate, short-term predictions people want, one would need to identify a reliable precursor - some signal that we could observe that tells us that a big quake is imminent.
Any number of possible precursors have been suggested and explored. Many seemed promising, but none has stood up to rigorous examination. So far as we have been able to tell, the earth simply does not provide any observable signal to tell us a big quake is on the way. What we know for sure is that preparedness remains our best defense against devastating earthquakes.
The earth does not reliably produce big earthquakes on full moons, notwithstanding the predictions that have come out of the woodwork for the days around this month's especially big full moon. (Recall that the moon was unremarkably new on the day the Japan quake struck.) So, when seismologists are asked whether earthquakes can be predicted, we tend to be quick to answer no, mindful of the years of research and experience in the field of seismology.
Sometimes even seismologists forget that in many of the ways that matter most, earthquakes are TOO predictable. We call it forecasting. This means we know where the active earthquake zones are on the planet. And, for many if not most of these zones, we have quite good estimates, based on various types of data, of the expected long-term average rates of earthquakes. We can say with some confidence that, in many of these zones, the next Big One might not be within the lifetime of any individual alive today but is very likely to occur within the lifetime of many of the buildings being constructed today. Any active plate boundary is fair game for a big earthquake, any time.
The scientific consensus is that the monster quakes, approaching and exceeding magnitude 9, are restricted to subduction zones such as the one where a magnitude-9 earthquake triggered the Japan tsunami. Along the type of plate boundary found in California and Turkey, among other places, the Big One might be "merely" magnitude 8. Pointing to any one corner of the Earth as the location of the next Big One is not a winning game. Take a map of the world's most active plate boundaries and throw a dart; where it lands is as good a guess as any. The only valid reason for imminent concern about any particular area is, oddly enough, right after a big earthquake has struck. Take Japan for example, where the risk from aftershocks is substantial.
Many people reading this might be tempted to feel thankful that they are not living within one of the planet's hot zones. Who in their right mind would live in California, anyway? Well, guess what.
There are places where big quakes are especially unlikely (but not impossible) - for example, central Canada. But there are other notable places where scientists know that damaging earthquakes are entirely possible. Southeastern Missouri; Charleston, South Carolina; Boston - these regions have all experienced earthquakes larger than the magnitude-6.1 Christchurch, New Zealand, event , just within the short historic record. A magnitude-6.1 quake under Boston, or any city along the Atlantic seaboard, would be unlikely but would not shock any earth scientist. At present, many scientists are pessimistic that prediction will ever be possible, although the jury is still out. Research continues with increasingly sophisticated methods and data.
What we know for sure is that preparedness remains our best defense against devastating earthquakes. As tragic as the disaster in Japan is, it clearly would have been much worse without that country's decades of investment in preparedness - the stringent building codes, early warning systems, tsunami systems and citizen education. It is sobering to consider the potential aftermath of a huge, or even pretty big, earthquake in parts of the world where preparedness efforts have lagged. If the risks seem hypothetical, now is a good time to ask, are they acceptable?
TSUNAMI / FREAK WAVES / ABNORMAL TIDES -
JAPAN - The monster tsunami which left the nuclear power plant on the brink of meltdown measured at least 14 metres high (46 feet). The Tokyo Electric Power Co. (TEPCO) had earlier estimated the height of the wave at 10 metres at its Fukushima No.1 plant, some 250km north-east of Tokyo. The massive 9.0-magnitude quake on March 11 triggered colossal waves along the country's Pacific coast, crippling the plant's cooling systems and prompting emergency operations to prevent fuel rods from melting and spewing radioactive material. "Now we estimate the height at more than 14 metres. We have found traces of the tsunami at such elevations." The wave was 14 metres high when it passed through the plant's parking area. A tsunami can surge to an elevation higher than its height at the time when it hits shore. The stricken plant's twin complex, some 10km to the south, was also hit by the tsunami but received less extensive damage.
A subcontract worker at the Fukushima No.2 plantsaid that he evacuated to a hill immediately after the quake crushed an embankment and broke the arm of a crane at his plant. "There was a backwash which left the seabed clearly seen some 200 metres offshore from the beach. Then the tsunami approached all at once and surged onto the plant. The tsunami cleared high above the dyke and came rushing down to wash away one parked car after another. I was very scared." The plants were designed to withstand earthquakes of magnitudes up to 8.0 and tsunami waves of up to 5.7 metres at the No.1 plant and 5.2 metres at the No.2.
TROPICAL STORMS -
No current tropical cyclones.
Some Vanuatu cyclone victims say they're still to receive food supplies two months later. - There are reports more than two thousand people on the east of Tanna island in the southern province of Vanuatu are still waiting for food supplies two months after being hit by a damaging cyclone. Local chiefs say food gardens were badly affected by Cyclones Vania and Atu but they haven’t received food from the government, despite supplies being sent to the wider region. They say their areas were the most affected by the cyclones, last year’s El Nino and the increase in activity of the Yasur volcano, and they deserve to get aid ahead of other areas in Tafea Province. The National Disaster Management Office admits it didn’t have enough rice when it began distributing supplies around Tafea last month. The office says it’d been given the wrong information after a survey of the damage caused by the cyclones.
New Cyclone Belt May Be Forming Off Brazil - An area of disturbed weather swirling about 300 miles east of Rio de Janeiro was dubbed Subtropical Storm Ariani by the Brazilian Navy. The U.S. National Hurricane Center said Arani was far less organized that Cyclone Catarina, which developed in the South Atlantic almost exactly seven years ago, in March 2004. Tropical or subtropical storms are VERY RARE in the region. Records indicate that three have formed since 2004, and the storms were unheard of before that time. Catarina destroyed about 1,500 homes, damaging around 40,000 others when it made an unprecedented landfall in southern Brazil. Tropical Storm Anita formed on March 12 last year far off the Brazilian coast. All three storms developed at the same point in March, almost to the day, in a possible indication that climate change is creating another tropical cyclone belt during late summer off Brazil’s South Atlantic coast.
SPACE WEATHER -
HERE COMES TROUBLE? A big sunspot is emerging over the sun's southeastern limb, and it is crackling with activity. NASA's Solar Dynamics Observatory recorded a surge of EXTREME ultraviolet radiation from the sunspot's magnetic canopy on March 21st. This appears to be the return of old sunspot 1165, last seen in early March when it formed on the sun's southwestern limb. Since then it has been transiting the far side of the sun, apparently growing in size and restlessness. The potential for trouble will become more clear in the hours ahead as the active region emerges in full.