The US Geological Survey reported Thursday that a 1.5-magnitude earthquake jiggled the area in northeast Wisconsin at 12:15 a.m. Tuesday, which the agency said would be enough to set off the sounds described as underground fireworks or thunder by many of the city’s 4,500 residents. Despite its low magnitude, it is not uncommon that earthquakes of its size are heard in addition to being felt, the USGS says. All earthquakes generate seismic energy that can move through the earth’s surface at thousands of miles per hour, creating a loud boom. The earthquake is responsible for a single boom that lasted one or two seconds, making it likely that the series of booms heard over several days in Clintonville were caused by a series of smaller earthquakes than the one recorded. “We can assume that there were others that were smaller than this one." While the noises have subsided since they were first reported early Monday morning, many have continued each night through Thursday. Dozens of residents have complained that the sounds have triggered cracks in their walls and floors and are responsible for rattling dishes. Public meetings were held Wednesday and Thursday to relay information to residents and take down their stories.
The Clintonville city administrator said the earthquake explanation is not conclusive because “in other places in the United States, a 1.5 earthquake would not be felt.” On the other hand, one possibility that makes Clintonville an exception is that “the type of rock that Wisconsin has transmits seismic energy very well.”
A geologist at the University of Wisconsin at Green Bay agrees that it is “certainly possible” that the underground noises are related to an earthquake, but says an earthquake of its magnitude would only produce noise “equivalent to 10 pounds of high explosives.” And because the sounds would take place at such a significant depth, it is likely they “would be muffled. The fact that the people are hearing bangs and sharp noises at such high frequency suggests [the sounds] are really close to the surface." One possibility he is proposing is that a dry winter is causing the earth’s underground water table to dry up, causing granite rocks to settle into the gaps, creating the loud noise. On Thursday the city hired an engineering firm in Waukesha to study the earth’s surface at different points of the city. An online map hosted on the city’s website traces the locations of the emergency calls dating back to Monday. There are plans to plot the phone calls to create a map that may determine patterns in where and when the sounds took place.
While it is uncommon for Wisconsin to get earthquakes, it is not unprecedented. The most powerful earthquake to hit the state was in 1947 when a 4.0-magnitude tremor affected over 3,000 square miles in the southwest region of the state.
than mere physical strength,
and the spiritual fiber of a nation
is more important than its wealth.**
Dwight D. Eisenhower
LARGEST QUAKES -
This morning -
5.3 PACIFIC-ANTARCTIC RIDGE
5.0 IZU ISLANDS, JAPAN REGION
5.1 REGION METROPOLITANA, CHILE
5.5 SOUTH AUSTRALIA
Australia's BIGGEST EARTHQUAKE IN 15 YEARS rattles Outback - The earthquake struck the outback community of Ernabella, in the far north of the state of South Australia. People living near the epicentre have reported being shaken, but otherwise escaping unscathed.
7.4 Mexico quake belatedly claims 2 lives - Two people caught in this week's big earthquake died Thursday, the first deaths reported from the temblor that damaged hundreds of homes in southern Mexico and caused panic far off in the national capital. In the Cuajinicuilapa municipality in Guerrero state, one of the victims died from injuries caused by a wall falling on him and the other died of complications from a heart attack suffered during the quake. (video)
Montserrat - Increase in Seismic Activity at Montserrat Volcano Forces Zone Closure. New ash eruptions have occurred at Soufriere Hills volcano. The activity is probably caused by rising magma under the volcano. The ash emissions began at around 8 am local time on 23 March, following 2 volcanic earthquake swarms on 22 and 23 March.
The vents of the new activity are on the floor of the 11 February 2010 collapse scar, immediately south of the old English’s crater wall and to the west of the long-lived hottest fumarole previously identified. Fumarolic activity on the volcano increased markedly and a new steam fumarole was discovered on the NW side of the dome immediately behind Gages Mountain. The ash venting was pulsating and produced ash clouds reaching approx. 6000 feet above sea level (3000 feet above the volcano). At its peak, black jets of ash were seen rising a few hundred meters above the floor of the collapse scar. This type of activity is probably "phreatic" in origin, caused when superheated rock meets groundwater, which evaporates explosively and fragments rock into ash.
The volcano-tectonic earthquakes are related to fracturing rocks underneath, probably as a result of increases in pressure. It is likely that these pressure increases and the resulting earthquakes, along with the rising temperature driving the phreatic activity, are related to uprising magma below the volcano. Similar types of activity have occurred at Soufriere Hills Volcano up to several months prior to restarts in magma extrusion, for example in 2005 and 2008.
The Hawaiian Volcano Observatory website has gotten an upgrade, and now users can check out 14 webcams keeping tabs on Kilauea 24 hours a day. Until recently, the HVO website had shown only six Webcams.
Alaska - The alert at Mount Cleveland, an active stratovolcano located in Alaska's Aleutian Islands, has been downgraded due to lack of activity in the past 10 days, following a period of increased activity that included numerous small, explosive eruptions.
TSUNAMI / FREAK WAVES / ABNORMAL TIDES -
Japanese tsunami boat found off Canada - Adrift since the devastating earthquake and tsunami struck Japan last March, a Japanese fishing boat was found Friday drifting off western Canada - more than 5,633km from where it went missing. The 46-metre vessel was about 222km off British Columbia's Queen Charlotte Islands. Japanese officials said the boat was lost from Hokkaido after the March 11, 2011, earthquake and tsunami. It's owner is also listed as missing, but is not believed to have been on board. The boat - the first piece of large tsunami debris to reach North America - would have reached the coast in about 50 days, but will be removed before then.
TROPICAL STORMS -
No current tropical storms.
Philippines - Flash floods and landslides threaten Bicol and Southern Luzon today, even as a potential cyclone – a low-pressure area – continues to approach the Philippines and may enter the country's territory in two to three days.
Australia experienced its second wettest year on record in 2011, helped by Cyclone Yasi, the strongest storm to hit landfall anywhere in the world.
Warmer planet means more severe storms - A few degrees warmer doesn't sound like much, but if you have ever watched a tropical storm move over water that is just 2C warmer, you know it can make the difference between a slightly damaging category 1 storm and a catastrophic category 5.
EXTREME HEAT & DROUGHT / WILDFIRES / CLIMATE CHANGE -
Rate of extreme weather events increasing, Bulgarian meteorologist says - Past winter held Bulgaria in a prolonged icy and snowy grip. Arguably FOR THE PAST 60 YEARS, THERE HAD NOT BEEN A WINTER LIKE THIS ONE with heavy snowfalls and prolonged periods of sub-zero temperatures. It was not a question of record-low temperatures having been set but the fact that the country had gone for such long periods in winter without cycles of warming and cooling. In recent years, the rate of extreme weather events have been increasing, such as very high temperatures in summer, and the current UNUSUALLY WARM weather for this time of March.
In most parts of Bulgaria, recent days have seen maximum temperatures of about 20 degrees Celsius and in some places, RECORD-HIGH TEMPERATURES for the time of year have been set. At the end of March, minimum temperatures would fall to about zero, and there could even be light snow in some parts of the country, but this would winter’s "last gasp." But currently, the warmer temperatures should not be interpreted to mean that summer has begun.
SPACE WEATHER -
MIDNIGHT ROCKET PLUMES - On Tuesday, March 27th, between midnight and 3 am EDT, NASA plans a rapid-fire launch of five sounding rockets from the Wallops Flight Facility in Virginia. The rockets will deliver a chemical tracer to the upper reaches of Earth's atmosphere, forming milky white plumes that reveal high-speed winds at the edge of space. The display should be visible to the naked eye from coastal areas between South Carolina and New Jersey.
INCREDIBLE SUNSPOT AR1429 - Big sunspot AR1429, the source of so many strong flares and geomagnetic storms earlier this month, is still erupting. The active region produced a significant coronal mass ejection on March 24th at 00:39 UT. Because of the sunspot's location on the farside of the sun, this particular CME will not hit Earth. None of the inner planets will be affected.
Since March began, sunspot AR1429 has propelled CMEs into every corner of the solar system, stirring up stormy space weather around every planet and spacecraft. If the sunspot remains active for another week or so, it will turn back toward Earth for a new round of geoeffective eruptions.