Sunday, October 16, 2011

SATELLITE RE-ENTRY - The ROSAT X-ray observatory, launched in 1990 by NASA and managed for years by the German Aerospace Center (DLR), will return to Earth within the next two weeks. Current best estimates place the re-entry between Oct. 22nd and 24th over an unknown part of Earth. Although ROSAT is smaller and less massive than UARS, which re-entered on Sept. 24th, more of ROSAT could reach the planet's surface. This is because the observatory is made of heat-tolerant materials. According to a DLR study, as many as 30 individual pieces could survive the fires of re-entry. The largest single fragment would likely be the telescope's mirror, which is very heat resistant and may weigh as much as 1.7 tons.
Solar activity has strongly affected ROSAT's decay. Only a few months ago, experts expected the satellite to re-enter in December. However, they did not anticipate the recent increase in sunspot count. Extreme ultraviolet radiation from sunspots has heated and "puffed up" Earth's atmosphere, accelerating the rate of orbital decay. Even one day before re-entry, the estimate will only be accurate to within plus/minus five hours. All areas under the orbit of ROSAT, which extends to 53 degrees northern and southern latitude could be affected by its re-entry.

**Here’s to the crazy ones. The misfits. The rebels.
The troublemakers. The round pegs in the square holes.
The ones who see things differently. They’re not fond of rules.
And they have no respect for the status quo.
You can quote them, disagree with them, glorify or vilify them.
About the only thing you can’t do is ignore them.
Because they change things. They push the human race forward.
And while some may see them as the crazy ones, we see genius.
Because the people who are crazy enough to think
they can change the world are the ones who do.**
Steve Jobs

This morning -

Yesterday -
10/15/11 -

10/14/11 -

Earthquakes generate big heat in super-small areas - Most earthquakes that are seen, heard, and felt around the world are caused by fast slip on faults. While the earthquake rupture itself can travel on a fault as fast as the speed of sound or better, the fault surfaces behind the rupture are sliding against each other at about a meter per second. But the mechanics that underlie fast slip during earthquakes have eluded scientists, because it's difficult to replicate those conditions in the laboratory. "We still largely don't understand what is going at earthquake slip speeds, because it's difficult to do experiments at these speeds."
Now, experiments mimicking earthquake slip rates show that fault surfaces in earthquake zones come into contact only at microscopic points between scattered bumps, called asperities, on the fault. These tiny contacts support all the force across the fault. The experiments show that when two fault surfaces slide against other at fast slip rates, the asperities may reach temperatures in excess of 2,700 degrees Fahrenheit, lowering their friction. The localized, intense heating can occur even while the temperature of the rest of the fault remains largely unaffected, a phenomenon known as flash heating. "This study could explain a lot of the questions about the mechanics of the San Andreas Fault and other earthquakes."
The experiments simulated earthquake speeds of close to half a meter per second. The rock surfaces touched only at the asperities, each with a surface area of less than 10 microns — a tiny fraction of the total surface area. When the surfaces move against each other at high slip rates, the experiments revealed, heat is generated so quickly at the contacts that temperatures can spike enough to melt most rock types associated with earthquakes. Yet the intense heat is confined to the contact flashpoints; the temperature of the surrounding rock remained largely unaffected by these microscopic hot spots, maintaining a "room temperature" of around 77 degrees Fahrenheit. "You're dumping in heat extremely quickly into the contacts at high slip rates, and there's simply no time for the heat to get away, which causes the dramatic spike in temperature and decrease in friction. The friction stays low so long as the slip rate remains fast. As slip slows, the friction immediately increases. It doesn't take a long time for the fault to restrengthen after you weaken it. The reason is the population of asperities is short-lived and continually being renewed, and therefore at any given slip rate, the asperities have a temperature and therefore friction appropriate for that slip rate. As the slip rate decreases, there is more time for heat to diffuse away from the asperities, and they therefore have lower temperature and higher friction."
Flash heating and other weakening processes that lead to low friction during earthquakes may explain the lack of significant measured heat flows along some active faults like the San Andreas Fault, which might be expected if friction was high on faults during earthquakes. Flash heating in particular may also explain how faults rupture as "slip pulses," wrinkle-like zones of slip on faults, which would also decrease the amount of heat generated. If that is the case, then many earthquakes have been misunderstood as high-friction events.

In the Atlantic -
No current tropical storms.

In the Pacific -
-Tropical depression Irwin was located about 350 mi. (565 km) SW of the southern tip of Baja California. There are no coastal watches or warnings in effect.

Storms Kill 55 in Mexico, Central America - The death toll in Mexico and Central America climbed to 55 Saturday as torrential rain storms continued, causing deadly mudslides and massive flooding. More than 250,000 people were affected across the region -- 62,700 in Mexico, 118,704 in Guatemala, about 60,000 in El Salvador, 7,862 in Honduras and 4,463 in Nicaragua. Maximum nationwide alerts were maintained in Guatemala, El Salvador and Nicaragua, while disaster prevention authorities worked against the clock to evacuate thousands of people from the most vulnerable regions ahead of the rain which had been forecast for the upcoming days. The continuing presence of a storm system over southern Mexico "is expected to produce locally heavy rains over the Yucatan peninsula, Guatemala, Honduras, Belize, Cuba, Jamaica and the Cayman Islands during the next couple of days."
By Saturday, civil protection authorities had evacuated over 17,700 people in the five countries worst hit by the ongoing torrential rains caused last week by Hurricane Jova, Hurricane Irwin, Tropical Depression 12-E and two other independent storm systems. Guatemala's death toll rose to 23, after one reported missing was found dead, and the country's National Coordinating Agency for Disaster Reduction raised the number of affected people to as many as 118,704 from Friday's 55,000. The death toll in El Salvador rose by one to a total of seven, while the number in the neighboring Honduras rose to 10 as the continuous rains caused flooding in over 50 percent of southern Honduras. In Nicaragua, the death toll remained unchanged at eight, while in Mexico, the reported death toll was 10, up from eight previously. Mexico's National Meteorological Service warned that "intense rains are expected in the next 72 hours in southern Veracruz, Eastern Oaxaca, Chiapas, Tabasco and the Yucatan Peninsula," and people in all these states should be "extremely careful" of venturing out in regions with overflowing rivers or prone to soil erosions.
According to weather forecasts, southern Mexico and Central America are facing situations similar to Hurricanes Stan and Mitch, as months-long torrential rains from an intense 2011 hurricane season have left soils saturated with water and extremely vulnerable to landslides. Over 2,000 people were killed across southern Mexico, Guatemala and El Salvador in 2005 when heavy rains from Hurricane Stan caused landslides and flooding, while over 10,000 people were killed in Nicaragua and Honduras in the mudslides caused by Hurricane Mitch in 1998.


THAILAND fought to hold back floodwaters flowing towards Bangkok today as a spring tide hindered efforts to protect the city of 12 million people from the kingdom's worst inundation in decades. Inner Bangkok, which is ringed by floodwalls, has so far escaped major flooding, leaving areas outside the main city to bear the brunt of the rising waters. Sandbags have been piled alongside rivers and canals and the authorities have been racing to repair a dyke that burst on Thursday, causing a brief scare in suburbs in the north of the capital.
The floods, several metres deep in places, are currently affecting about one third of Thailand's provinces and have damaged the homes or livelihoods of millions of people and left at least 297 people dead. About 110,000 people around the country have sought refuge in shelters in the face of waters that have destroyed crops and inundated hundreds of factories in industrial parks north of Bangkok. "People have been affected by floods for three months now. The government understands that and is trying to drain the water as soon as possible. This incident is ONE OF THAILAND'S BIGGEST AND MOST SEVERE LOSSES IN HISTORY."
This weekend Bangkok is bracing for a large amount of run-off water along with seasonal high tides that will make it harder for the flood waters to flow out to sea. "We predict the water will be highest from October 16-18 as the high sea level combines with water from the north which will arrive in Bangkok tomorrow (Sunday)." The water in the Chao Phraya River had risen to 2.27 metres above sea level on Saturday morning at high tide, which was lower than expected. Overnight thunderstorms caused some minor flooding on roads in the centre of the capital, but the authorities have said they are confident they can prevent serious inundation in the low-lying city. The floods have dealt a heavy blow to Thailand's economy, disrupting production of cars, electronics and other goods. The floods began pouring into another major industrial estate in Ayutthaya, just north of the capital, today after the floodwalls were breached, prompting an evacuation order.