Recent studies estimate that one-third of the Delta's 70-some islands could flood in a magnitude 6.5 or greater earthquake due to levee failures. There is at least a 62 percent chance of such a quake striking the Bay-Delta region in the next 20 years. This vulnerability is a statewide concern. Delta water diversions irrigate about 3 million acres of California farmland, and 25 million people depend on the estuary for at least some of their drinking water. Widespread levee failures could contaminate that freshwater supply, perhaps for a year or longer.
It is not uncommon for quakes to occur where a fault has not been identified. In September 2000, for instance, a 5.0-magnitude quake struck in Napa on an unmapped fault, damaging a number of buildings. A key difference in this case is that earthquakes of any sort are rare within the Delta. Like Sacramento, the Delta is considered seismically tame compared to the Bay Area. About four years ago, USGS installed a network of seismic sensors in the Delta to better assess the risks. They found that ground motion in the Delta during a quake is as much as 10 times greater than areas outside the Delta. Basically, this means the Delta shakes more, likely because of the loose nature of the Delta's peat and sand soils. This could make its levees more vulnerable to collapse. Most research on quake risk in the Delta has focused on the threat from faults outside the estuary, notably the Hayward fault. But the Oct. 15 quake is a reminder that the Delta has its own faults, about which relatively little is known. All the mapped faults in the Delta are known as "blind" faults because they don't appear on the surface – likely because its peat and sand soils are deep and relatively fluid. A geologist believes there is a major north-south fault beneath the Delta that has yet to be mapped. "I think the seismic risk in the Delta has been underestimated, and we don't understand it. There may well be older pockets of peat buried in the Delta, and those might increase the seismic shaking." (map)
Gregg Easterbrook
LARGEST QUAKES -
This morning -
5.2 HINDU KUSH REGION, AFGHANISTAN
6.0 NEW IRELAND REGION, P.N.G.
5.1 BANDA SEA
5.4 GULF OF CALIFORNIA
5.1 SOLOMON ISLANDS
Yesterday -
10/27/10 -
5.0 SOUTHWEST OF SUMATRA, INDONESIA
5.3 SOUTHWEST OF SUMATRA, INDONESIA
5.1 SOUTHWEST OF SUMATRA, INDONESIA
5.0 SOUTHWEST OF SUMATRA, INDONESIA
5.0 GUAM REGION
5.3 SOUTH SANDWICH ISLANDS REGION
VOLCANOES -
INDONESIA - About 800 miles (1,300 kilometers) to the east of the tsunami hit area, in central Java the Mount Merapi volcano was mostly quiet but still a threat after Tuesday's eruption that sent searing ash clouds into the air, killing at least 33 people and injuring 17. A mass burial was planned for later Thursday. Among the dead was a revered elder who had refused to leave his ceremonial post as caretaker of the mountain's spirits. The discovery Wednesday of his ash-covered body, reportedly found in a position of Islamic prayer, kneeling face-down on the floor, rattled residents who for years joined his ceremonies to appease the rumbling giant by throwing rice, clothes and chickens into the crater. "I'm more afraid than ever," said a farmer from the mountain village of Pangukrejo. "Who's going to tell us what's going on with Merapi?"
On the ash-covered slopes of Mount Merapi, authorities continued a search for more victims. The eruption sent thousands streaming into makeshift emergency shelters, although the ash did not disrupt flights over Indonesia. About 36,000 people have been evacuated. Some defied authorities and returned home to check on crops and possessions left behind. More than 11,000 people live on Merapi's fertile slopes. Tuesday's blast eased pressure that had been building behind a lava dome on the crater. Experts warned that the dome could still collapse, causing an avalanche of the blistering gas and debris trapped beneath it.
TSUNAMI / FREAK WAVES / ABNORMAL TIDES -
INDONESIA - Fears are growing for the 379 people who are still missing in the aftermath of a tsunami which hit Indonesia on Monday. The death toll from a tsunami which struck a remote chain of islands has topped 311. Officials said the number could rise significantly because so many people were still unaccounted for. Bodies were being found on beaches and coastal areas of the Mentawai islands off the western coast of Sumatra, which took the full force of the tsunami triggered by an earthquake on Monday night.
Survivors said they had almost no warning that the 10-foot wall of water was bearing down on them, despite the laying of a sophisticated network of alarm buoys off the Sumatran coast. As the magnitude of the disaster sank in, many were asking whether the expensive warning system - established after the 2004 Asian tsunami which killed at least 168,000 people in Indonesia alone - had failed. An official tsunami warning was issued after the 7.7-magnitude quake but it either came too late or did not reach the communities in most danger. One survivor said that the wave slammed into his community on North Pagai island only 10 minutes after residents had felt the quake. "About 10 minutes after the quake we heard a loud, thunderous sound. We went outside and saw the wave coming. We tried to run away to higher ground but the wave was much quicker than us." Several continental plates meet in a deep ocean trench off the western coast of Sumatra, providing a constant source of seismic friction and potential disaster.
Aerial images from the tsunami-hit Mentawai Islands in Indonesia have revealed the extent of destruction. Flattened villages are plainly visible on the images, taken from helicopters circling the islands. Rescuers have finally reached the area where 13 villages were washed away by the 3m (10ft) wave, but 11 more settlements have not yet been reached. Rescue teams have still not arrived at the worst-affected communities, where the scale of the damage is still unclear.
The first cargo plane loaded with tents, medicine, food and clothes landed on the islands on Wednesday.
But officials have had less luck transporting goods by boat, some 175km (110 miles) across choppy seas from Padang. Rescue teams dispatched to the island were unable to send back adequate reports because lines of communication with the remote islands were so bad. Local disaster officials said more than 400 people were still missing, and 16,000 refugees had been moved to higher ground from the coastal areas. The first images emerging from the islands, taken on mobile phones, showed bodies being collected from empty clearings where homes and buildings once stood. Corpses were strewn along beaches and roads.
Locals were given no indication of the coming wave because an early-warning system put in place after the devastating 2004 tsunami had stopped working. Two buoys off the Mentawai islands were vandalised and out of service. "We don't say they are broken down but they were vandalised and the equipment is very expensive. It cost us five billion rupiah each (£353,000; $560,000). However, even a functioning warning system may have been too late for people in the Mentawai Islands.
TROPICAL STORMS -
-Cyclone 01S was 753 nmi ESE of Diego Garcia.
- Typhoon CHABA was 137 nmi SSE of Kadena AB, Okinawa
Tropical cyclone Giri caused more damage than predicted when it hit western Burma as a category 5 storm last Friday. Giri hit an isolated part of the country 250 miles northwest of the capital. With wind speeds up to 155 miles per hour, the storm was more powerful than Cyclone Nargis, which swept the country with 130 mph winds, claiming around 140,000 lives in 2008. The cyclone has affected about ten times more people than initially estimated.
“Over the weekend it looked like tens of thousands of people may be affected. We now estimate that 400,000 people have been affected." High winds and tidal surges have destroyed many homes in coastal areas and lack of clean water in affected regions is increasing the risk of disease transmission. About 70,000 people were left homeless and 170,000 had been affected by Giri. The storm killed 27 and 15 are still missing.
Tidal surges as high as 12 feet brought by Cyclone Giri have killed nine people and washed away seven villages in Pauk Taw Township in Arakan State. The seven villages that were washed away by the surge are Byin Thit, Kyauk Mong, Pyin Gri, Nga Ree Chai, Ree Pike Chai, Thea Dwe, and Nga Mea Byint, which are located on small Inn Gra Chai Island in the East Phon Ron Ga Archipelago, south of Arakan State's capital Sittwe. "As far as I know, all homes, monasteries and schools in the seven villages were washed away by a surge during the cyclone that hit the Arakan coast last Friday. The villages are now barren plains without any houses." Over 20,000 people in Pauk Taw Township were affected by the surge but there has been no government relief since the storm struck six days ago.
In Pauk Taw Township, several other villages located on islands were also destroyed by the storm and tidal surges. Those villages are Byin Daung, Saw Mae Kyi, Kalar Thein, Zi Shwe Maw, Kan Byin, Nga Pyi Tat, Ponna Gyi, and Sun Bike Village on Myay Ngu Island. Burmese officials announced that 27 people were killed by Cyclone Giri when it hit the Arakan coast, but many people believe the confirmed death toll will be higher than that. A youth leader from Kyauk Pru, an area hit hard by the cyclone, said that the death has risen to 93. Among the casualties are nine residents from Pauk Taw, twelve from Min Bya, one from Kyauk Pru , and 71 from Mray Bon Township, where 80 fishing boats were reportedly sunk by the storm.
ATLANTIC - A nearly-stationary low pressure system in the eastern Atlantic Ocean could develop into Tropical Storm Shary.The system is located about 1,200 miles northwest of the northernmost Cape Verde Islands. The National Hurricane Center says it has become better organized. There is a 50 percent chance of this system becoming a tropical cyclone in the next 48 hours and a 60% chance for a nearby one.
SEVERE RAIN STORMS, FLOODING, LANDSLIDES -
INDONESIA - Extreme Weather Causes Flood in Jakarta. Floods causing a terrible traffic jam in Jakarta Monday were presumably because of extreme weather change. Extreme weather condition has resulted in the rainfall reaching 111 millimeters in just 2 hours. In fact, normally, rainfall in one month only reaches 300 millimeters. In this situation the existing drainage can not accommodate the rainfall and drain the river water properly. Consequently, the water overflows to the streets. "The fact is that the yesterday`s rainfall was not normal."
The rapid development of the storm that dominated most of the central US on October 26th, is now in the record books. Low pressure was recorded at 28.25" in Minnesota, THE LOWEST PRESSURE EVER FOR A NON-TROPICAL SYSTEM IN THE U.S. That was equal to the pressure in a Category 3 Hurricane. The winds are slowed down over land, as opposed to the open ocean. Winds did reach over 70 mph, resulting in 268 wind damage reports. There were also 24 reports of tornadoes. Power was out for more than 200,000 people, planes were grounded, and many buildings were damaged. The rapid development of this storm can be seen from the satellite movie from NOAA's GOES project. This is stronger than the storm that capsized the Edmund Fitzgerald ship on Lake Superior back on November 10, 1975. It also BREAKS THE RECORD LOW PRESSURE set in Baltimore from the Superstorm of March 1993. There is still one more day of active weather possible. A slight risk of severe storms will be from Maryland southward. (video & maps)
SPACE WEATHER -
A pair of UNUSUAL fireballs over Canada and the southeastern USA have experts wondering if Comet Hartley 2 might produce a meteor shower in early November. This month, Comet Hartley 2 has put on a good show for backyard astronomers. The comet has a vivid green atmosphere and auburn tail of dust. Could this comet produce a meteor shower? "Probably not, but the other night we saw something that makes me wonder."
On Oct 16th, a pair of NASA all-sky cameras caught an unusual fireball streaking across the night sky over Alabama and Georgia. It was bright, slow, and - here's what made it unusual - strangely similar to a fireball that passed over eastern Canada less than five hours earlier. Because the fireballs were recorded by multiple cameras, it was possible to triangulate their positions and backtrack their orbits before they hit Earth. This led to a remarkable conclusion: "The orbits of the two fireballs were very similar. It's as if they came from a common parent."
There's a candidate only 11 million miles away: Small but active Comet Hartley 2 is making one of the closest approaches to Earth of any comet in centuries. It turns out that the orbits of the two fireballs were not only similar to one another, but also roughly similar to the orbit of the comet. Moreover, meteoroids from Comet Hartley would be expected to hit Earth's atmosphere at a relatively slow speed -just like the two fireballs did. This could be a coincidence. "Thousands of meteoroids hit Earth's atmosphere every night. Some of them are bound to look like 'Hartley-ids' just by pure chance." Even so, keep an eye out for more in the nights ahead, especially on Nov. 2nd and 3rd. That's when a potential Hartley-id meteor shower would be most intense. The comet was closest to Earth on Oct. 20th, but that's not necessarily the shower's peak-time. "The comet has been sputtering space dust for thousands of years, making a cloud that is much bigger than the comet itself. Solar radiation pressure and planetary encounters cause the comet and the dust cloud to diverge — not a lot, but enough to make the date of the shower different from the date of the comet's closest approach." If there is a Hartley-id shower, it would emanate from the constellation Cygnus the Swan, visible to observers in the northern hemisphere almost directly overhead after sunset in early November. "It's probably going to be a non-event. On the other hand, we might discover a whole new meteor shower." (photos)
Behemoth sunspot 1117 is not merely growing, it is transmogrifying [transforming, especially in a surprising or magical manner.] Since yesterday, the shape-shifting sunspot has developed a "beta-gamma" magnetic field that harbors energy for M-class solar flares. Any such eruptions will likely be geoeffective because the sunspot is almost-squarely facing Earth. (photo at link above)
