Earthquakes...

Buildings destroyed due to earthquake.

An earthquake (also known as a quake, tremor or temblor) is the result of a sudden release of energy in the Earth's crust that creates seismic waves. The seismicity, seismism or seismic activity of an area refers to the frequency, type and size of earthquakes experienced over a period of time.
Earthquakes are measured using observations from seismometers. The moment magnitude is the most common scale on which earthquakes larger than approximately 5 are reported for the entire globe. The more numerous earthquakes smaller than magnitude 5 reported by national seismological observatories are measured mostly on the local magnitude scale, also referred to as the Richter magnitude scale. These two scales are numerically similar over their range of validity. Magnitude 3 or lower earthquakes are mostly almost imperceptible or weak and magnitude 7 and over potentially cause serious damage over larger areas, depending on their depth. The largest earthquakes in historic times have been of magnitude slightly over 9, although there is no limit to the possible magnitude. The most recent large earthquake of magnitude 9.0 or larger was a 9.0 magnitude earthquake in Japan in 2011 (as of March 2014), and it was the largest Japanese earthquake since records began. Intensity of shaking is measured on the modified Mercalli scale. The shallower an earthquake, the more damage to structures it causes, all else being equal.
At the Earth's surface, earthquakes manifest themselves by shaking and sometimes displacement of the ground. When the epicenter of a large earthquake is located offshore, the seabed may be displaced sufficiently to cause a tsunami. Earthquakes can also trigger landslides, and occasionally volcanic activity.
In its most general sense, the word earthquake is used to describe any seismic event — whether natural or caused by humans — that generates seismic waves. Earthquakes are caused mostly by rupture of geological faults, but also by other events such as volcanic activity, landslides, mine blasts, and nuclear tests. An earthquake's point of initial rupture is called its focus or hypocenter. The epicenter is the point at ground level directly above the hypocenter.

Recently Nepal has been triggered by the earthquake which cause a huge disaster.The 2015 Nepal earthquake (also known as the Gorkha earthquake),which killed more than 7,000 people and injured more than twice as many,occurred at 11:56 NST on 25 April, with a moment magnitude (M_w) of 7.8M_w^[1] or 8.1M_s^[2] and a maximum Mercalli Intensity of IX (Violent). Its epicenter was the village of Barpak, Gorkha district, and its hypocenter was at a depth of approximately 15 km (9.3 mi).

It was the most powerful disaster to strike Nepal since 1934. Some casualties have been reported in the adjoining areas of India, China, and Bangladesh.

The earthquake triggered an avalanche on Mount Everest, killing at least 19,making it the deadliest day on the mountain in history.It triggered another huge avalanche in Langtang valley, where 250 are now missing.

Hundreds of thousands of houses were destroyed rendering people homeless with entire villages flattened,across many districts of the country. Centuries-old buildings were destroyed at UNESCO World Heritage sites in the Kathmandu Valley, including some at the Kathmandu Durbar Square, the Patan Durbar Square and the Bhaktapur Durbar Square. Geophysicists and other experts had warned for decades that Nepal was vulnerable to a deadly earthquake, particularly because of its geology, urbanization, and architecture.

International Aid has been provided to Nepal which was proved to very helpful. India was the first to respond within hours, being Nepal's immediate neighbour, with Operation Maitri which provided rescue and relief by its armed forces It also evacuated its own and other countries' stranded nationals.

UNICEF appealed for donations, as close to 1.7 million children had been driven out into the open, and were in desperate need of drinking water, temporary shelters, sanitation and protection from disease outbreak due to rotting dead bodies, as well as psychological counseling as of 29 April 2015. It distributed water, tents, hygiene kits, water purification tablets and buckets

On 26 April 2015, international aid agencies and governments mobilized to respond to the earthquake. However, they faced challenges in getting assistance to the country and struggled to distribute it amid the widespread devastation, especially in areas cut-off, outlying the capital, Kathmandu The global response was coordinated by the Nepalese government through its National Emergency Operation Center.however, relief efforts were hampered by skepticism of pilferage, resulting in a tussle over control of the distribution of funds and aid, aid mismatch, congestion and customs delay at Kathmandu's airport and border check posts. As of 2 May 2015 Nepal's finance minister said they not received pledged donations in cash. The list below gives it's break-up by each nation, along with the aid in kind delivered immediately. On 3 May, the airport was closed to large aircraft after its runway sustained damage from the flights delivering aid.

Earthquake Precautions

What to Do After an Earthquake ?

DO'S

• If any damage is suspected, turn the system off from the main valve or, switch.
• Clean up household chemical spills, toxic and flammable materials to avoid any chain of unwanted events.
• Gather information and necessary instructions from battery operated radios.
• Obey Public safety precautions.
• Leave a message stating where you are going if you must evacuate your residence.
• Take your earthquake survival kit with you.
• It should contain all necessary items for your protection and comfort.
• Check your water and electrical lines for defects.

DON'T s

• Do not fill the overhead tank completely.
• Do not carry out haphazard repairs.
• Repairs should be done only under the supervision of a structural engineer.
• Do not put additional supports without the guidance of an experienced/qualified structural engineer.
• Do not use the lift until it has been checked and certified by thelift company.

"Remember the precautions to take, if you feel the Earth shake."