(I hope to purchase a laptop by next week
so that I can finally post the updates while I'm away.)
This morning -
5.0 TONGA
5.1 SOUTH OF TONGA
5.1 GUATEMALA
Yesterday -
4/22/12 -
5.0 KEP. TANIMBAR REGION, INDONESIA
5.0 HOKKAIDO, JAPAN REGION
5.0 WEST OF MACQUARIE ISLAND
5.2 WEST OF MACQUARIE ISLAND
5.3 SOLOMON ISLANDS
Live Seismograms - Worldwide (update every 30 minutes)
MYSTERY BOOMS -
Boom, light in California, Nevada probably meteor - 4/22/12 - A loud explosion heard across much of Nevada and California on Sunday morning rattled homes and prompted a flood of calls to law enforcement agencies on both sides of the Sierra Nevada, some reporting fireball sightings. The sound and the light show were probably caused by a meteor that entered Earth's atmosphere, astronomers said. "It knocked me off my feet and was shaking the house. It sounded like it was next door." No damage or injuries were reported. Some people reported seeing a brilliant light streak across the sky at the same time. Sightings occurred over roughly a 600-mile line across the two states, including Reno, Elko and North Las Vegas in Nevada, and the San Francisco, Sacramento and Bakersfield areas in California. Astronomers said they believe the mysterious light was a fireball, which is a very bright meteor. It will take time to determine the path of the fireball and where it broke up. "From the reports, I have no doubt it was a fireball. It happens all the time, but most are in daytime and are missed. This one was extraordinarily bright in the daylight." It's "pretty rare" for fireballs to produce a loud explosion. For that to happen the meteor must have survived intact until breaking up about 5 miles above Earth. Most fireballs are visible at 50 miles above Earth. "I have been looking at the sky for 30 years, and I have never witnessed something so amazing and puzzling. It is an event that makes you glad to be alive," said a man in San Francisco. "The main body was bright green, and the head was bright red and white." "People are putting two and two together and saying it has something to do with the meteor shower. But the fireball was probably coincidental and unrelated to the peak of the meteor shower."
Meteor Explosion Shocks Locals - The meteor explosion went off around 8 am. "We were all just getting up, getting ready to get the day going and all of a sudden we heard a loud bang," says a Truckee resident. "I thought somebody hit the house." He wasn't the only one baffled by the boom. Others heard the blast from Winnemuca, to Reno, to Bakersfield. That's when the speculation started. It's likely a very bright meteor called a fireball that fragmented and hit the earth's surface somewhere in a 600 mile radius in the Sierra-Nevada mountains. "It's RARE to see and hear a fireball,. this was very clearly heard and the breakup of it was very clearly heard and I'm fairly certain that's what that was." It happened just after the peak of the annual Lyrid meteor shower. "I think this is unrelated to the meteor shower, because meteor showers don't produce this kind of thing, but stray rocks in space will be spectacular, and loud, and bright, and look like fire balls across the sky."
TROPICAL STORMS
No current tropical storms.
HEAVY SNOW / EXTREME COLD -
Dynamic storm will affect U.S. and Canadian east - The National Weather Service at State Park, Pennsylvania has used strong wording for this system: A LATE SEASON…HEAVY AND DESTRUCTIVE SNOWSTORM IS POSSIBLE SUNDAY NIGHT THROUGH TUESDAY MORNING. On Saturday evening (April 21), an area of low pressure was strengthening across the Gulf of Mexico and pushing into Florida, which resulted in a tornado watch for parts of central and southern Florida. As this system pushes northeast, it will rapidly intensify, with a barometric pressure equivalent to a strong tropical storm or Category 1 hurricane (~990 millibars). It's ironic that New England could see their biggest snows outside of the winter months. Autumn snow occurred around October 30, 2011 when a strong area of low pressure pushed into New England. Now, a spring storm will produce heavy snow in parts of eastern West Virginia, western Pennsylvania, and parts of the northern Appalachian Mountains that stretch into parts of Virginia and North Carolina. Parts of eastern Ontario and Quebec could see snowy weather and even freezing rain from this storm as well. If this storm developed in the middle of January, the issues would likely not be as significant because many of the leaves on the trees would be nonexistent. However, everything is in full bloom. Heavy snow and strong winds will be easily captured by the trees, and this could result in numerous power outages. In higher elevations, snowfall totals could accumulate over a foot, but areas likely will not get that much snow. Generally, three to five inches are possible, with a maximum of ten inches in higher elevations. Rainfall will be welcomed into the region as parts of the U.S. East Coast have been particularly dry. Rainfall totals should add up to one to three inches along the coast. A majority of New England are in flood watches. (maps)
SPACE WEATHER -
Approximately every 11 years the magnetic field on the sun reverses completely - the north magnetic pole switches to south, and vice versa. It's as if a bar magnet slowly lost its magnetic field and regained it in the opposite direction, so the positive side becomes the negative side. But, of course, the sun is not a simple bar magnet and the causes of the switch, not to mention the complex tracery of moving magnetic fields throughout the eleven-year cycle, are not easy to map out. This flip coincides with the greatest solar activity seen on the sun in any given cycle, known as "solar maximum." Currently the polarity at the north of the sun appears to have decreased close to zero - that is, it seems to be well into its polar flip from magnetic north to south - but the polarity at the south is only just beginning to decrease. "Right now, there's an imbalance between the north and the south poles. The north is already in transition, well ahead of the south pole, and we don't understand why." The asymmetry described in recent research papers belies models of the sun that assume that the sun's north and south polarities switch at the same time. In addition, both papers agree that the switch is imminent at the north pole, well in advance of general predictions that solar maximum for this cycle will occur in 2013. Lastly, the direct Hinode results also suggest a need to re-examine certain other solar models as well. Measuring the magnetic activity near the poles isn't easy because all of our solar telescopes view the sun approximately at its equator, offering only an oblique view of the poles, when they require a top-down view for accurate magnetic measurements. It was discovered in 2003 that as the sun moves toward solar maximum, giant eruptions on the sun, called prominence eruptions - which during solar minimum, are concentrated at lower solar latitudes - begin to travel toward higher latitudes near the poles. In addition, the polar brightness in the microwave wavelengths declines to very low values. "These prominence eruptions are associated with increased solar activity such as coronal mass ejections or CMEs, so CMEs originating from higher latitudes also point to an oncoming solar maximum. When we start to see prominence eruptions above 60 degrees latitude on the sun, then we know that we are reaching solar maximum." By mapping the brightness of microwave radiation throughout the chromosphere, the scientists showed that the intensity at the north pole has already dropped to the threshold that was reached in the last solar maximum cycle, suggesting the onset of solar max there. This is backed by the fact that prominence eruptions are also occurring at high latitudes in the north. Eruption activity in the south half of the sun, however, is only just beginning to increase - the first CME occurred there in early March 2012. The Hinode data also shows this discrepancy between the north and the south. The magnetic map of the poles of every month since September of 2008 showed large, strong concentrations of magnetic fields that are almost all magnetically negative in polarity. Recent maps, however, show a different picture. Not only are the patches of magnetism smaller and weaker, but now there is a great deal of positive polarity visible as well. What once pointed to a strongly negative north pole, is now a weakly magnetized, mixed pole that will become neutral - which occurs at solar maximum - within the month according to the team's predictions. "This is the first direct observation of this field reversal. And it is extremely important to understanding how the sun's magnetism generates the solar cycle." Typical models of the magnetic flip, suggest that as active regions rotate around the equator, their higher, trailing edge - which is almost always the opposite polarity from the pole in their hemisphere - drift upward, eventually dominating the status quo and turning positive to negative or negative to positive. The Hinode data show that this transition at the north began BEFORE such drifting had a chance to occur. "This is one of the most interesting things in this Hinode paper to me. How did the polar reversal start so early, even though the onset of the solar cycle, that is, increased activity at lower latitudes, hadn't begun yet?" The idea that asymmetries exist in the sun is not completely new. Other work has recently emphasized symptoms of this asymmetry, measuring, for example, more sunspots in the northern hemisphere than in the south at the moment. "But most of the well-developed models don't incorporate the asymmetry in them. More complicated models that incorporate asymmetries do exist, but they have other ways in which they fail to match observations." Scientists will keep their eye on the current cycle - numbered Solar Cycle 24 - because a polar switch at the north that is sooner than was expected also implies this may be a fairly small cycle in terms of the number of sunspots and amount of solar activity.
