Sunday, May 13, 2012

Possibly active fault under Mount Fuji to trigger big quake, landslide? - Mount Fuji, Japan's highest peak, may be sitting on a large, active fault that could trigger quakes and landslides that would change the mountain's shape and devastate nearby communities, the education ministry said on Thursday. A survey commissioned by the ministry found an 18-mile fault beneath Japan's highest mountain, believed by many to be sacred, and research results indicate it is likely to be active.
"We're not certain if it's an active fault. But there is a possibility ... A structural investigation near [the volcano] found a fault. Because there's a fault there, there's a chance that it's moving." If the fault sets off an earthquake, it could lead to a major landslide and hit communities at the foot of the 12,400-foot-high mountain. Further research is required, the official said. Little is known about the seismic structure under Mount Fuji because faults were buried by mudflows triggered by a huge landslide that occurred about 2,600 to 2,900 years ago, as well as by layers of volcanic ash.
However, scientists say there is evidence the mountain has collapsed in the past. "In this region, there is a stratum right above the fault that indicates that Mount Fuji has collapsed before." An earthquake in 1707 caused Fuji to erupt and that killed an estimated 20,000 people.

**Happy Mother's Day!**

Live Seismograms - Worldwide (update every 30 minutes)

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New Zealand - A swarm of earthquakes has rattled the South Island but seismologists don't believe there is any cause for alarm. The latest quake struck just before 3pm and was centred in the Christchurch suburb of Cashmere. It measured 3.9 on the Richter scale but was strongly felt across the city as it occurred at a depth of just 5km. There were no immediate reports of damage from the quake but it left residents rattled as it was the first big aftershock to hit the city in some months. ''The noise was huge."
 ''I have been waiting for another biggie, let's hope it isn't a foreshock but just in case I am filling my water bottles and getting things ready." ''The whole building really shook and there was quite a bit of noise with it.'' Earlier in the day Southland was struck by two quakes, the largest of which measured 5.5 and was centred 40km west of Tuatapere at a depth of 12km. The ground shook vigorously but it was not a violent quake. ''It was very strong but nothing was thrown off the walls or fell off the shelves." The quake was preceded by a magnitude 2.8 quake centred in roughly the same area. A magnitude 4.3 quake also struck the Kaikoura region Saturday morning. It was centred 30km east of Kaikoura at a depth of 15km.
It is not unusual to see so many earthquakes in one day and it is unlikely the quakes were a forerunner to a more significant seismic event.

India - Moderate quake jolts northeast, 2 hurt, several buildings damaged in Assam. An earthquake measuring 5.4 on the Richter scale jolted some northeastern states, including Assam, in which at least two labourers were injured in a wall collapse while several buildings were damaged. One house collapsed and cracks appeared in some buildings in the quake, which had its epicentre in Guwahati, the main commercial city of the mineral- and tea-rich state of Assam.

No current tropical storms.

Odd 92L in the Atlantic - An area of disturbance called 92L is surprisingly well organized for this time of year and this far north [400 miles southwest of the Azores], but it shouldn't really surprise everyone that this is happening. SST anomalies are already 1-2C above average in that area, so it's MORE TYPICAL OF JULY as it is. Satellite reveals a tight, well organized core with great spiral banding, and showing a system that is already detaching from the front that it has been associated with for the past few days.
 It's sudden uptick in convection though is VERY UNNATURAL, and it looks well on it's way to become Sub-Tropical or Tropical Storm Alberto perhaps as soon as early today. Determining whether or not this is a warm-core system or a hybrid is difficult, but most if not all the of the phase-diagrams indicate that this system is transitioning from a symmetric cold core system to a symmetric warm core system, which is what a tropical cyclone is. However, given that the wind-radius and surface pressure is so far spread out, plus it's association with the front near by (similar to Sean in 2011), it would be sub-tropical in nature.
These systems are VERY RARE in the Atlantic. It would be only the third tropical storm to occur in May since 1981. It was first seen in 2005 with the infamous Hurricane Vince, but was once again seen in a very similar fashion in Tropical Storm Grace. In both cases, our basic understanding of tropical formations were defied when both of these systems developed in HIGHLY UNUSUAL locations, generally considered too hostile for formations, and thrived in those environments.
The dilemma exists however on how to name it. These systems are similar to Polar Lows, so determining the difference between the two is difficult. However, 92L does not meet the requirement exactly for a Polar Low, so what it is? For now, the NHC settles on it being a sub-tropical cyclone. In any case, the NHC will be waiting for consistency to name 92L. If it continues to look like this in say 6 hours, it is probable that it could be named as soon as Saturday night.
The storm's heavy thunderstorms have weakened some during the afternoon, making it less likely NHC will be inclined to name it; the fact that 92L is over waters of 66°F (19°C) hurts its chances. Forecasters believe it has a 40 percent chance of turning into a subtropical or tropical cyclone during the next 48 hours. 92L does not have long to live in either case, as hostile wind shear should overcome this system in 48 hours or so. (satellite photo)


Afghanistan - Flash flooding in the northern Afghan province of Takhar killed at least 20 people and injured fifteen others. Five people are also believed to be missing after the flood struck late Thursday. Houses and livestock were swept away by the raging waters. "Dozens of villages have been hit by the flood, I'm worried that the death toll will go up."
 The flood was the second to strike the region this month. On May 6, 40 people died and dozens more were missing after flooding in the nearby Sar e Pol province. Some 100 people have died in flooding in Afghanistan over the past month, as snow thaws in the lead up to the warmer season lead to rising water levels.

China - The death toll from hail and rain storms in a mountainous area in northwest China has risen to 40. Another 18 people are missing and power supplies and telecommunications networks have been disrupted in Minxian county in Gansu province. Nearly 30,000 people were evacuated following the storm, which battered the county on Thursday. Relief teams have taken blankets and clothing into the area.

Could a Changing Climate Set Off Volcanoes and Quakes? - A British scientist argues that global warming could lead to a future of more intense volcanic eruptions and earthquakes. And while some dismiss his views as preposterous, he points to a body of recent research that shows a troubling link between climate change and the Earth’s most destructive geological events. There is, he argues, growing evidence to incriminate changing climate in the planet’s most destructive geological events.
Melting ice sheets and changes in sea level can, he maintains, set off the largest earthquakes and volcanic eruptions. Indeed, thanks to climate change, a human hand may already be at work. The most solid evidence for climatic influence on geology comes from the end of the last ice age, around 12,000 years ago. This period of rapid climate change, when ice sheets retreated from much of the planet, coincided with a sudden outburst of geological activity. The incidence of volcanic eruptions in Iceland increased around 50-fold for about 1,500 years, before settling back to previous levels.
He makes the case that during the long preceding glaciation, the weight of ice some two kilometers thick over Iceland maintained high pressures underground that kept magma at the root of volcanoes solid and suppressed eruptions. But as the ice melted, the huge.weight was released and the land surface lifted, sometimes by hundreds of meters. This reduced the pressure below. “Reduction of pressure enabled mantle rocks to melt, creating a zone of magma upwelling underneath Iceland.” Magma production increased 30-fold – that magma, the argument goes, burst out in a spectacular epidemic of volcanic eruptions.
Similar, though less pronounced, surges in volcanic activity occurred at that time across much of the planet, wherever large ice sheets or small tropical glaciers melted. From the Eifel mountains of Germany to the Chilean Andes, and from California to Kamchatka, volcanoes were awakened. While the planet’s volcanoes have been relatively peaceful during the long stable climate since then, he warns that we need to watch out as the world starts to warm once more.
“Volcanoes can be incredibly sensitive to tiny changes to their external environment, constantly teetering on the edge of stability." In the Northern Hemisphere, eruptions happen most frequently between November and April. The reason, they say, is shifts in water round the globe. This movement of water slightly squashes or releasing the land beneath, at times pushing magma to the surface rather like toothpaste in a tube.
Over the past 40 years, El Nino cycles in the tropical Pacific Ocean have triggered a regular seismic response as the pressure of water has changed with short-term sea level fluctuations. There are more earthquakes in the eastern Pacific in the months after the cycle lowers sea levels in the area by a few centimeters, which flexes the plates beneath. A 2009 study concluded that something as seemingly insignificant as low atmospheric pressure in the heart of typhoons was sufficient to trigger slow earthquakes in strata east of Taiwan.
Some researchers are unconvinced by all this. Some geologists have expressed skepticism about any immediate cause for concern. So how scared should we be? The short answer is nobody knows. While clearly some geological responses to surface events could occur fast, others could take thousands of years to emerge.