Seismologists have searched for early-warning signals of earthquakes for more than a century. These range from small tremors in the ground, to aurora-like lights in the atmosphere and even to bizarre animal behaviour. But despite a few records of such incidents coming before quakes – usually noted retrospectively – there has never been any consistent method to accurately predict when a major shock is going to happen. Many scientists still monitor various parameters around quake-prone regions in the hope that they will improve forecasting, or perhaps open up avenues towards prediction.
These parameters include infrared emissions in the upper atmosphere and the total electron content (TEC) of the ionosphere – the part of the Earth's atmosphere between altitudes of 80 and 1000 kilometres that is made up of electrons and ions. Changes in both infrared emissions and TEC are known to occur for non-seismic reasons: the infrared varies with cloud cover, for instance, while TEC gets a boost during heightened solar activity. Researchers claim that they can pick out anomalous behaviour in the infrared and TEC that coincided with various past quakes, such as the 2008 Sichuan earthquake in China and the 2010 Haiti earthquake. Now researchers in California claim to have evidence of anomalous infrared and TEC signals shortly before the magnitude 9.0 earthquake that struck off the coast of Tohoku, Japan, on 11 March this year. The researchers believe that the apparent anomalies could be evidence that major seismic activity is preceded by a release of radon gas that ionizes and heats the surrounding air.
The group retrospectively analysed four parameters: the Earth's outgoing infrared radiation, using satellite imaging; the ionosphere's TEC, calculated from global positioning satellite signals; the cross-section or "tomography" of the ionosphere, using data from low-Earth-orbit satellites; and the density of upper-ionosphere electrons, calculated from signals taken at four Japanese ground-based ionosonde stations. The infrared data was analysed for the month of March over a period of eight years – from 2004 to 2011 – while the ionospheric data was analysed only for around the time of the Tohoku quake.
The researchers found what they say is the first indication of an infrared anomaly on 8 March 2011, three days before the quake. By 11 March, the day of the quake, the location of the maximum infrared emission apparently fell exactly over the quake's epicentre. Meanwhile, they also found an increase in electron density, reaching a maximum on 8 March. This day also showed an abnormal variation in TEC over the epicentre, according to the findings. On 3–11 March the ionosondes recorded a "large increase" in electron density.
Yet many seismologists are sceptical about the benefits of such analyses, believing that it is easy to find correlations when data is taken selectively. Signals in the atmosphere and ionosphere "fluctuate all the time, and it would be surprising if some fluctuation did not occur around the time of the earthquake. One of the things you can predict about earthquakes is that following the event there will be claims of precursory behaviour identified in retrospect." A seismologist at California Institute of Technology in the US is also sceptical of prediction. "Through the years I have seen dozens of reported anomalous geophysical signals. However, we have yet to discover a precursor to an earthquake that reliably produces a significant signal before it occurs. In fact, the more we look, the more it seems as though a large earthquake starts similarly to a small earthquake." Due to the similarities, even an advance signal would not help to judge the intensity of an upcoming earthquake.
Still, the group are hopeful that their work will help both forecasting and prediction. They have listed more than 100 earthquakes during the last decade and have discovered a "systematic appearance of atmospheric and ionospheric signals in the same time frame we have shown for the Tohoku earthquake".
will be victorious.**
Sun Tzu
LARGEST QUAKES -
This morning -
5.6 BONIN ISLANDS, JAPAN REGION
5.3 SOUTHERN IRAN
Yesterday -
6/14/11 -
5.6 NORTHERN SUMATRA, INDONESIA
5.5 NORTHERN SUMATRA, INDONESIA
5.3 NEAR EAST COAST OF HONSHU, JAPAN
5.8 OFF EAST COAST OF HONSHU, JAPAN
5.2 HOKKAIDO, JAPAN REGION
5.0 OFF E. COAST OF S. ISLAND, N.Z.
5.0 SOUTHEAST OF LOYALTY ISLANDS
5.0 NEW IRELAND REGION, P.N.G.
NEW ZEALAND - Shallow aftershock rocks Christchurch as experts warn of more earthquakes. The probability of another major earthquake hitting the devastated New Zealand city of Christchurch in the next year has increased in the wake of this week's new tremors. The already traumatised South Island city was rocked by major quakes on Monday, with a 5.0-magnitude aftershock at a depth of just 1km rattling the nervous residents again early Tuesday. No new damage was caused by Tuesday's aftershock, which was followed by others including a 4.2-magnitude shake at 2.30pm local time.
The most recent quakes - which come after the February 22 disaster that killed 182 people - have been blamed on a new faultline in the region. New calculations by GNS Science showed that from today until June 15 next year there was now a 30 per cent chance of a quake of between magnitude 6.0 and 6.9 striking the area, compared with a 23 per cent probability expressed last month. Monday's major aftershocks has probably reduced the stress buildup in one area, but transfered it further east and offshore. The increased likelihood of danger will do nothing to soothe the shattered nerves of residents, who have been struggling to rebuild their city in the wake of February's deadly 6.3-magnitude quake which caused up to $NZ20 billion ($16.3bn) damage.
As of today there were still 1500 people without power, 15 per cent of the city had no water, sewage services were cut to some parts of the city and 16 roads were closed. The damage bill in the wake of Monday's quakes, which killed one person, was put as high as $NZ6 billion. New Zealand's Treasury department has not yet provided estimates of costs of the latest earthquakes.
New fault found below Canterbury - A previously undiscovered fault capable of generating a magnitude-7 earthquake has been found by scientists investigating bedrock off Christchurch. Analysis of the Canterbury earthquakes is being carried out by teams of scientists. They have found a previously unknown "complex arrangements of faults" in the bedrock under Canterbury and offshore under Pegasus Bay.
One of those was an offshore fault about 25km long - similar in length to the Greendale fault which caused the original Canterbury earthquake on September 4. It is part of a widespread network of faults in basement rocks in the bay. Most were millions of years old and "very slow moving" - though a small number of faults showed evidence of reactivation in the more recent geological past. "There are younger fault structures that are active and they are reactivating the older faults." However, there was no strong evidence of aftershocks in the region migrating toward Pegasus Bay at present.
"Understanding the earthquake hazard for the coming years and decades requires an assessment of all the faults in the region, and learning about their rates of activity and earthquake potential." Data has revealed several previously unknown fault structures, mostly trending northeast-southwest. They were likely to be the bedrock structures on which the magnitude-5.3 Boxing Day and magnitude-6.3 February 22 earthquakes occurred. "They appear to be very old faults in the basement rock that may have been weakly reactivated. Cantabrians live in a seismically active area, and finding previously unknown faults that seem to have very long intervals between ruptures won't have significantly increased the level of earthquake hazard in the region."
Even before the investigation started, it was widely known that there were several dozen active faults within an 80km radius of Christchurch and many were capable of producing a damaging earthquake. Most of the newly discovered faults had their major period of movement prior to about 50 million years ago. "The focus of the investigation is to identify the length, orientation and spatial arrangement of faults in the aftershock zone in Canterbury. For an earthquake of magnitude-6 or greater to be generated, a fault of 10km or more in length is needed."
VOLCANOES -
No signs Chile volcano easing - The Chilean volcano spewing dangerous ash high into the sky, sowing air travel havoc, could have even more intense eruptions in the days to come, government geologists have warned. It is possible there will be a return to increased eruptive activity" of the Puyehue volcano in southern Chile's Andes mountains, which started belching fumes on June 4. They were detecting no let-up in the volcano's emissions, which were towering eight kilometres into the troposphere. It maintained its alert level at "moderate eruption".
That was bad news for airlines flying into or over Chile, Argentina, Uruguay, Paraguay, southern Brazil, and Australia. Passengers in those regions have had to ditch aircraft for travel by boat or overland, or cancel plans entirely. The chaos recalled the massive paralysis of air travel over Europe in 2010 when an Icelandic volcano erupted. Uruguay, which lies across a river from Buenos Aires, did resume some air traffic by Tuesday, although 70 flights were cancelled during the day. Buenos Aires airports have suspended domestic and international flights for several days now, and Chile's meteorological service said prevailing winds would continue to blow the ash into Argentina through today. With flight disruptions also in Australia, it marks THE FIRST TIME IN 20 YEARS THAT AN ASH CLOUD FROM AN ERUPTING SOUTH AMERICAN VOLCANO HAS TRAVELLED HALFWAY ACROSS THE GLOBE.
The eruption could run its course within a week, but it was hard to know based on precedent. The volcano's last major eruption in 1960 lasted two weeks, but an earlier one in 1921 lasted two months. The June 4 eruption has been hardest for tourist areas near the volcano like Argentina's alpine-style resort of Bariloche, where the airport has been closed for a week, and Villa Angostura, which is 30km away. The Argentine government today declared an agricultural emergency in three southern provinces, although the agriculture ministry noted in a press release that "in no case was there ash of more than 15 centimetres".
Puyehue's eruption sent columns of debris 10,000 metres high, blanketing the picturesque mountains and lakes along the Chile-Argentina border in a snowy white ash and prompting the evacuation of 3500 people. Chile's National Emergencies Office kept its alert in the red for the area around the volcano.
African Volcano Ash Cloud Crisis Eases - The ash cloud from the erupting Nabro volcano in the northeast African nation of Eritrea is continuing to spread throughout east Africa and the Middle East. Disruption to air traffic is expected to be minimal, however, in comparison to the widespread cancellation of flights during the eruptions of the Grímsvötn (Iceland) and Puyehue (Chile) volcanoes.The eruption has reduced to a continuous emission of mainly SO2. Forecast charts show concentrated levels of ash confined below FL350 (35,000 ft) in Ethiopia and Sudan. Satellite imagery still shows Monday’s ash moving northeastwards over Egypt and the Middle East, but it should start to diffuse over the next 24 hours. Officials in the Ethiopian capital, Addis Ababa, expressed hope that rain forecast for late Tuesday would help the ash cloud to dissipate.
TROPICAL STORMS -
No current tropical storms.
SEVERE RAIN STORMS, FLOODING, LANDSLIDES -
AUSTRALIA - Major flooding is expected in drenched towns from the NSW north coast to the Hunter Valley following three days of wild weather. More than 1500 people have been evacuated, with 400 locals leaving their homes and businesses in Kempsey in search of higher ground. The Macleay River, which runs through the town, is expected to peak at 6.9 metres this afternoon. "Which is a major flood. It's above major now."
As much as 78mm of rain had fallen in Kempsey in the 24 hours to 10am (AEST), while 276mm of rain had fallen at nearby Bellbrook since Sunday. Severe weather warnings remain in place in the NSW Hunter region and on the north coast. "Today the focus will be on monitoring the complex low weather system as it shifts towards the Hunter." Towns that have already copped a drenching include Turners Flat, which had been inundated with 234mm of rain since Sunday, and Aldavilla, got 245mm during the same period. Residents at Fernbank, North Shore and Settlement Point areas of Port Macquarie are expected to be isolated later today and about 700 residents from Smithtown, Jerseyville, Gladstone and Kinchella were ordered to evacuate by early this morning.
EXTREME HEAT & DROUGHT / WILDFIRES / CLIMATE CHANGE -
Fire on all Sides: New Mexico Battles Wallow Fire and Two More - New Mexico is battling two major fires on opposite ends of the state – in the southwest, Arizona’s gigantic Wallow Fire, and in the northeast, a Colorado-border wildfire. The embattled state is also fighting a third fire in the southeast that closed down Carlsbad Caverns National Park.
The Wallow Fire, close to becoming the largest wildfire in Arizona’s history, has caused local New Mexico officials to warn Luna residents that they might be ordered to evacuate at any time. The two-week-old blaze has burned somewhere between 452,000 to 463,000 acres as of Monday night. It could surpass Arizona’s largest fire, the 2002 Rodeo-Chediski Fire, which scorched 468,000 acres, as soon as Tuesday. Despite its size, however, the Wallow Fire is not as destructive structure-wise as the Rodeo-Chediski. It has only destroyed 31 homes, compared to the 465 homes lost to the Rodeo-Chediski. As of Monday, the Wallow Fire is 18 percent contained. Firefighters have mostly taken control of the northern edge of the Wallow Fire, and are working furiously to fend off the eastern part of the Wallow Fire that is threatening Luna. They are setting strategic fires in New Mexico to burn off fuel and keep the Wallow Fire from growing in the state.
In the opposite corner of New Mexico, along the Colorado border, another wildfire has grown from 100 acres to about 6,000 acres in less than 24 hours on Monday. The fire along the New Mexico-Colorado border began on Sunday and has forced about 1,000 people to be ordered to evacuate in the town of Raton, N.M. It has also closed down the main north-south highway since Sunday afternoon.
And in southeastern New Mexico, the Loop fire near the Carlsbad Caverns National Park has burned about 3,000 acres as of Monday. Hundreds of victors and workers were evacuated on Monday from the national park. The Loop fire is currently zero percent contained.
