Series of Earthquakes in Recent Past - Are we Prepared ?

Moved by frequent reports of Earth Quakes reported very often in last many months. As part of Planetary Society, India's aims and objectives this article as been prepared to show the status and provide information on Earth Quakes as on 17th April,2010.

Here is list of Significant Earth Quakes in 2010 as on 17th April,2010 :
1.    Magnitude 4.9 UTAH April 15, 2010
2.    Magnitude 6.9 SOUTHERN QINGHAI, CHINA April 13, 2010
3.    Magnitude 6.3 SPAIN April 11, 2010
4.    Magnitude 6.8 SOLOMON ISLANDS April 11, 2010
5.    Magnitude 7.7 NORTHERN SUMATRA, INDONESIA April 06, 2010
6.    Magnitude 7.2 BAJA CALIFORNIA, MEXICO April 04, 2010
7.    Magnitude 4.4 GREATER LOS ANGELES AREA, CALIFORNIA March 16, 2010
8.    Magnitude 6.7 OFFSHORE BIO-BIO, CHILE March 16, 2010
9.    Magnitude 6.5 NEAR THE EAST COAST OF HONSHU, JAPAN March 14, 2010
10.  Magnitude 6.9 LIBERTADOR O HIGGINS, CHILE March 11, 2010
11.  Magnitude 6.1 EASTERN TURKEY March 08, 2010
12.  Magnitude 6.8 SOUTHERN SUMATRA, INDONESIA March 05, 2010
13.  Magnitude 6.6 OFFSHORE BIO-BIO, CHILE March 05, 2010
14.  Magnitude 8.8 OFFSHORE MAULE, CHILE February 27, 2010
15.  Magnitude 7.0 RYUKYU ISLANDS, JAPAN February 26, 2010
16.  Magnitude 6.9 CHINA-RUSSIA-NORTH KOREA BORDER REGION February 18, 2010
17.  Magnitude 3.8 ILLINOIS February 10, 2010
18.  Magnitude 5.9 OFFSHORE NORTHERN CALIFORNIA February 04, 2010
19.  Magnitude 6.2 BOUGAINVILLE REGION, PAPUA NEW GUINEA February 01, 2010
20.  Magnitude 5.9 HAITI REGION January 20, 2010
21.  Magnitude 4.0 OKLAHOMA January 15, 2010
22.  Magnitude 7.0 HAITI REGION January 12, 2010
23.  Magnitude 6.5 OFFSHORE NORTHERN CALIFORNIA January 10, 2010
24.  Magnitude 4.1 SAN FRANCISCO BAY AREA, CALIFORNIA January 07, 2010
25.  Magnitude 6.8 SOLOMON ISLANDS January 05, 2010
26.  Magnitude 7.1 SOLOMON ISLANDS January 03, 2010
27.  Magnitude 6.6 SOLOMON ISLANDS January 03, 2010

Here is the List of 59 Earthquakes Occurred in last 15 Days click here above 5.0 magnitude.

MAP of Recent Earthquakes - Last 8-30 Days USGS
1. Tremors in 3 mandals of Kadapa district - 28th Feb, 2010  The Hindu Click here 1,  Deccan Chronicle  Click Here 2
2.  Mild tremors in Visakhapatnam- 31st March, 2010 The Hindu  Click here 1 , 
Siasat News Paper Click here 2 

Here is the compilation of series of videos etc.. to understand EarthQuake :


Is Recent Earthquake Activity Unusual?
Following is sourced from USGS i.e. U.S. Geological Survey Office of Communication Release.
Dated 14th April

China’s tragic magnitude 6.9 earthquake on April 13 and the recent devastating earthquakes in Haiti, Chile, Mexico, and elsewhere have many wondering if this earthquake activity is unusual.
Scientists say 2010 is not showing signs of unusually high earthquake activity. Since 1900, an average of 16 magnitude 7 or greater earthquakes — the size that seismologists define as major — have occurred worldwide each year. Some years have had as few as 6, as in 1986 and 1989, while 1943 had 32, with considerable variability from year to year.

With six major earthquakes striking in the first four months of this year, 2010 is well within the normal range. Furthermore, from April 15, 2009, to April 14, 2010, there have been 18 major earthquakes, a number also well within the expected variation.

“While the number of earthquakes is within the normal range, this does not diminish the fact that there has been extreme devastation and loss of life in heavily populated areas,” said USGS Associate Coordinator for Earthquake Hazards Dr. Michael Blanpied.

What will happen next?
Aftershocks will continue in the regions around each of this year’s major earthquakes sites. It is unlikely that any of these aftershocks will be larger than the earthquakes experienced so far, but structures damaged in the previous events could be further damaged and should be treated with caution. Beyond the ongoing aftershock sequences, earthquakes in recent months have not raised the likelihood of future major earthquakes; that likelihood has not decreased, either. Large earthquakes will continue to occur just as they have in the past.

Though the recent earthquakes are not unusual, they are a stark reminder that earthquakes can produce disasters when they strike populated areas — especially areas where the buildings have not been designed to withstand strong shaking. What can you do to prepare? Scientists cannot predict the timing of specific earthquakes. However, families and communities can improve their safety and reduce their losses by taking actions to make their homes, places of work, schools and businesses as earthquake-safe as possible.

 Can Humans be a reason for Earthquakes ? Axing our own legs - Nations Blind folded in so called Development Process !
 While most earthquakes are caused by movement of the Earth's tectonic plates, human activity can also produce earthquakes. Four main activities contribute to this phenomenon: constructing large dams and buildings, drilling and injecting liquid into wells, and by coal mining and oil drilling.

Perhaps the best known example is the 2008 Sichuan earthquake in China's Sichuan Province in May; this tremor resulted in 69,227 fatalities and is the 19th deadliest earthquake of all time. The Zipingpu Dam is believed to have fluctuated the pressure of the fault 1,650 feet (503 m) away; this pressure probably increased the power of the earthquake and accelerated the rate of movement for the fault.

The greatest earthquake in Australia's history was also induced by humanity, through coal mining. The city of Newcastle  was built over a large sector of coal mining areas. The earthquake was spawned from a fault which reactivated due to the millions of tonnes of rock removed in the mining process.

The effects of earthquakes include, but are not limited to, the following:

Shaking and ground rupture :
Shaking and ground rupture are the main effects created by earthquakes, principally resulting in more or less severe damage to buildings and other rigid structures. The severity of the local effects depends on the complex combination of the earthquake magnitude, the distance from the epicenter, and the local geological and geomorphological conditions, which may amplify or reduce wave propagation.The ground-shaking is measured by ground acceleration.

Specific local geological, geomorphological, and geostructural features can induce high levels of shaking on the ground surface even from low-intensity earthquakes. This effect is called site or local amplification. It is principally due to the transfer of the seismic motion from hard deep soils to soft superficial soils and to effects of seismic energy focalization owing to typical geometrical setting of the deposits.

Ground rupture is a visible breaking and displacement of the Earth's surface along the trace of the fault, which may be of the order of several metres in the case of major earthquakes. Ground rupture is a major risk for large engineering structures such as dams, bridges and nuclear power stations and requires careful mapping of existing faults to identify any likely to break the ground surface within the life of the structure.

Landslides and avalanches : 
Earthquakes, along with severe storms, volcanic activity, coastal wave attack, and wildfires, can produce slope instability leading to landslides, a major geological hazard. Landslide danger may persist while emergency personnel are attempting rescue.

Fires :
Earthquakes can cause fires by damaging electrical power or gas lines. In the event of water mains rupturing and a loss of pressure, it may also become difficult to stop the spread of a fire once it has started. For example, more deaths in the 1906 San Francisco earthquake were caused by fire than by the earthquake itself.

Soil liquefaction :
Soil liquefaction occurs when, because of the shaking, water-saturated granular material (such as sand) temporarily loses its strength and transforms from a solid to a liquid. Soil liquefaction may cause rigid structures, like buildings and bridges, to tilt or sink into the liquefied deposits. This can be a devastating effect of earthquakes. For example, in the 1964 Alaska earthquake, soil liquefaction caused many buildings to sink into the ground, eventually collapsing upon themselves.

Tsunamis are long-wavelength, long-period sea waves produced by the sudden or abrupt movement of large volumes of water. In the open ocean the distance between wave crests can surpass 100 kilometers (62 miles), and the wave periods can vary from five minutes to one hour. Such tsunamis travel 600-800 kilometers per hour (373-497 miles per hour), depending on water depth. Large waves produced by an earthquake or a submarine landslide can overrun nearby coastal areas in a matter of minutes. Tsunamis can also travel thousands of kilometers across open ocean and wreak destruction on far shores hours after the earthquake that generated them.

Ordinarily, subduction earthquakes under magnitude 7.5 on the Richter scale do not cause tsunamis, although some instances of this have been recorded. Most destructive tsunamis are caused by earthquakes of magnitude 7.5 or more.

Flood : A flood is an overflow of any amount of water that reaches land.Floods occur usually when the volume of water within a body of water, such as a river or lake, exceeds the total capacity of the formation, and as a result some of the water flows or sits outside of the normal perimeter of the body. However, floods may be secondary effects of earthquakes, if dams are damaged. Earthquakes may cause landslips to dam rivers, which then collapse and cause floods.

The terrain below the Sarez Lake in Tajikistan is in danger of catastrophic flood if the landslide dam formed by the earthquake, known as the Usoi Dam, were to fail during a future earthquake. Impact projections suggest the flood could affect roughly 5 million people.

Tidal forces : Research work has shown a robust correlation between small tidally induced forces and non-volcanic tremor activity.

Human impacts :
Earthquakes may lead to disease, lack of basic necessities, loss of life, higher insurance premiums, general property damage, road and bridge damage, and collapse or destabilization (potentially leading to future collapse) of buildings. Earthquakes can also precede volcanic eruptions, which cause further problems; for example, substantial crop damage, as in the "Year Without a Summer" . Damaged infrastructure, one week after the 2007 Peru earthquake Is one of the best example in recent past.

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