What is an earthquake and what causes them to happen?
An earthquake is caused by a sudden slip on a fault. Stresses in the earth's outer layer push the sides of the fault together. Stress builds up and the rocks slips suddenly, releasing energy in waves that travel through the earth's crust and cause the shaking that we feel during an earthquake. An EQ occurs when plates grind and scrape against each other. In California there are two plates the Pacific Plate and the North American Plate. The Pacific Plate consists of most of the Pacific Ocean floor and the California Coast line. The North American Plate comprises most the North American Continent and parts of the Atlantic Ocean floor. These primary boundary between these two plates is the San Andreas Fault. The San Andreas Fault is more than 650 miles long and extends to depths of at least 10 miles. Many other smaller faults like the Hayward (Northern California) and the San Jacinto (Southern California) branch from and join the San Andreas Fault Zone. The Pacific Plate grinds northwestward past the North American Plate at a rate of about two inches per year. Parts of the San Andreas Fault system adapt to this movement by constant "creep" resulting in many tiny shocks and a few moderate earth tremors. In other areas where creep is NOT constant, strain can build up for hundreds of years, producing great EQs when it finally releases.
|Great||8 and higher||1 Â¹|
|Major||7 - 7.9||17 Â²|
|Strong||6 - 6.9||134 Â²|
|Moderate||5 - 5.9||1319 Â²|
|Light||4 - 4.9||13,000 (estimated)|
|Minor||3 - 3.9||130,000 (estimated)|
|Very Minor||2 - 2.9||1,300,000 (estimated)|
|Â¹ Based on observations since 1900. |
Â² Based on observations since 1990.
Number of Earthquakes Worldwide for 2000 - 2005. Located by the US Geological Survey National Earthquake Information Center
|8.0 to 9.9||1||1||0||1||2||1|
|7.0 to 7.9||14||15||13||14||14||9|
|6.0 to 6.9||158||126||130||140||140||116|
|5.0 to 5.9||1345||1243||1218||1203||1509||1307|
|4.0 to 4.9||8045||8084||8584||8462||10894||10264|
|3.0 to 3.9||4784||6151||7005||7624||7937||5782|
|2.0 to 2.9||3758||4162||6419||7727||6317||3249|
|1.0 to 1.9||1026||944||1137||2506||1344||20|
|0.1 to 0.9||5||1||10||134||103||0|
|Total||22256||23534||27454||31419||* 31199||* 21390|
|1.||Chile||1960 05 22||9.5||-38.24||-73.05|
|2.||Prince William Sound, Alaska||1964 03 28||9.2||61.02||-147.65|
|3.||Off the West Coast of Northern Sumatra||2004 12 26||9.0||3.30||95.78|
|4.||Kamchatka||1952 11 04||9.0||52.76||160.06|
|5.||Off the Coast of Ecuador||1906 01 31||8.8||1.0||-81.5|
|6.||Northern Sumatra, Indonesia||2005 03 28||8.7||2.08||97.01|
|7.||Rat Islands, Alaska||1965 02 04||8.7||51.21||178.50|
|8.||Andrean of Islands, Alaska||1957 03 09||8.6||51.56||-175.39|
|9.||Assam - Tibet||1950 08 15||8.6||28.5||96.5|
|10.||Kuril Islands||1963 10 13||8.5||44.9||149.6|
|11.||Banda Sea, Indonesia||1938 02 01||8.5||-5.05||131.62|
|12.||Chile-Argentina Border||1922 11 11||8.5||-28.55||-70.50|
|Largest Earthquakes||Deadliest Earthquake|
Northern Sumatra, Indonesia
|03/28||8.7||1,313||Northern Sumatra, Indonesia|
|2004||12/26||9.0||283,106||Off West Coast of Northern Sumatra||12/26||9.0||283,106||Off West Coast of Northern Sumatra|
|2003||09/25||8.3||0||Hokkaido, Japan Region||12/26||6.6||31,000||Southeastern Iran|
|2002||11/03||7.9||0||Central Alaska||03/25||6.1||1,000||Hindu Kush Region, Afghanistan|
|2001||06/23||8.4||138||Near Coast of Peru||01/26||7.7||20,023||India|
|2000||11/16||8.0||2||New Ireland Region, P.N.G.||06/04||7.9||103||Southern Sumatera, Indonesia|
|1998||03/25||8.1||0||Balleny Islands Region||05/30||6.6||4,000||Afghanistan-Tajikistan Border Region|
|1997||10/14||7.8||0||South of Fiji Islands||05/10||7.3||1,572||Northern Iran|
|12/05||7.8||0||Near East Coast of Kamchatka|
|1996||02/17||8.2||166||Irian Jaya Region Indonesia||02/03||6.6||322||Yunnan, China|
|1995||07/30||8.0||3||Near Coast of Northern Chile||01/16||6.9||5,530||Kobe, Japan|
|10/09||8.0||49||Near Coast of Jalisco Mexico|
|1993||08/08||7.8||0||South of Mariana Islands||09129||6.2||9,748||India|
|1992||12/12||7.8||2,519||Flores Region, Indonesia||12/12||7.8||2,519||Flores Region, Indonesia|
|1991||04/22||7.6||75||Costa Rica||10/19||6.8||2,000||Northern India|
|1990||07/16||7.7||1,621||Luzon, Philippine Islands||06/20||7.4||50,000||Iran|
|Lat( Deg N )||Long( Deg E )|
|1819 Jun 16||23.6||68.6||Kutch,Gujarat||8.0|
|1869 Jan 10||25||93||Near Cachar, Assam||7.5|
|1885 May 30||34.1||74.6||Sopor, J&K||7.0|
|1897 Jun 12||26||91||Shillongplateau||8.7|
|1905 Apr 04||32.3||76.3||Kangra, H.P||8.0|
|1918 Jul 08||24.5||91.0||Srimangal, Assam||7.6|
|1930 Jul 02||25.8||90.2||Dhubri, Assam||7.1|
|1941 Jun 26||12.4||92.5||Andaman Islands||8.1|
|1943 Oct 23||26.8||94.0||Assam||7.2|
|1950 Aug 15||28.5||96.7||Arunachal Pradesh-China Border||8.5|
|1956 Jul 21||23.3||7.0||Anjar, Gujarat||7.0|
|1967 Dec 10||17.37||73.75||Koyna, Maharashtra||6.5|
|1975 Jan 19||32.38||78.49||Kinnaur, Hp||6.2|
|1988 Aug 06||25.13||95.15||Manipur-Myanmar Border||6.6|
|1988 Aug 21||26.72||86.63||Bihar-Nepal Border||6.4|
|1991 Oct 20||30.75||78.86||Uttarkashi, Up Hills||6.6|
|1993 Sep 30||18.07||76.62||Latur - Osmanabad, Maharashtra||6.3|
|1997 May 22||23.08||80.06||Jabalpur, MP||6.0|
|1999 Mar 29||30.41||79.42||Champoli, UP||6.8|
|2001 Jan 26||23.40||70.28||Bhuj, Gujarat||6.9|
Seismic Zonation map of a country is a guide to the seismic status of a region and its susceptibility to earthquakes. India has been divided into five zones with respect to severity of earthquakes. Of these, zone v is seismically the most active where earthquakes of magnitude 8 or more could occur recent strong motion observations around the world have revolutionized thinking on the design of engineering structures, placing emphasis also on the characteristics of the structures themselves it should be realized that in the case of shield type earthquakes, historic data are insufficient to define zones because recurrence intervals are much longer than the recorded human history this may often give a false sense of security. Occurrence of the damaging earthquake at Latur, falling in zone I is a typical example of this situation.
Q: During an Earth Quake (EQ), should you head for the doorway?
Ans: Yes, only if you live in an old, unreinforced adobe. In modern homes, doorways are no stronger than any other parts of the house and usually have doors that will swing and can injure you. You are safer practicing the duck, cover, and hold under a sturdy piece of furniture.
Q: What emergency supplies do I need?
Q: How can I plan ahead for an Earth Quake?
Q: What should I do during an EQ?
Q: Things Not to do during an EQ?
Q: What can I expect in my house when an EQ occurs? How do I identify it? What can be done?
Ans: The contents of your home may be damaged and can be dangerous:
What Can Be Done: You can install door latches, braces and fasteners to fix most of these hazards yourself.
Q: What do I do after an earthquake?
Q: What are the steps to EQ safety/awareness?
Q: What are part of the earthquake Supplies and Equipment Checklist?
Ans: When organizing supplies for an earthquake, remember that you need to get to them after an earthquake has turned your house into mess. Store supplies in an easy to find location that has a minimal chance of being buried under falling objects. If you are short on space, a large trashcan makes an excellent storage container. If you live in an apartment, the container can be hidden under a decorative tablecloth. Earthquakes can happen at any time. Are you prepared right now? Have you rotated your food supplies in the last six months? If not, make time on your calendar. Do it now!
Q: What are the sanitation supplies one need to carry during the EQ?
Q: What are the structural precautions one can take while constructing house to avoid the risk of EQ?
The majority of residential structural damage is caused by homes sliding off their foundations during major earthquakes.
Q: What should one do when people comeback home from the disaster?
Ans: Returning home after a major disaster can be both dangerous and difficult. Do not return home until authorities have indicated that it is safe to do so.
Remember that it takes a long time to recover from a disaster. Take your time and pace yourself. Plan a reasonable amount of activity each day. Include children in clean-up and recovery activities. Watch for signs of stress in yourself and family members. If you can't shake feelings of despair, get professional help. While life will not be the same as before the disaster happened, you can and will recover.
The behavior of your pets may change after an emergency. Normally quiet and friendly pets may become aggressive or defensive. Watch animals closely. If after a disaster you have to leave town, take your pet with you. Pets are unlikely to survive on their own.
Try to stay at home and avoid driving to keep roads clear for emergency workers.
If you have appropriate insurance, call your agent. Take pictures of damages. Keep good records of repair and cleaning costs.
If you smell, gas or hear a blowing or hissing sound, open a window and quickly leave the building. Turn off the gas at the outside main valve if you can, and call the gas company from a neighbor's home. If you turn off the gas for any reason, it must be turned back on by a professional.
If you see sparks, broken or frayed wires, or if you smell hot insulation, turn off the electricity at the main fuse box or circuit breaker; call an electrician first for advice.
If you suspect sewage lines are damaged, avoid using the toilets and call a plumber. If water pipes are damaged, contact the water company and avoid using water from the tap. You can obtain safe water by melting ice cubes.
If any of the electrical appliances are wet, turn off the main power switch in the house. Unplug the appliance, dry it out, then reconnect it and turn off the main power switch back on.
If fuses or circuits blow when the electrical power is restored, turn off the main power switch again and inspect for short circuits in the home wiring or appliances. Call a professional if the problem continues to occur.
Q: What is an earthquake and what causes them to happen?
Ans: An earthquake is caused by a sudden slip on a fault. Stresses in the earth's outer layer push the sides of the fault together. Stress builds up and the rocks slips suddenly, releasing energy in waves that travel through the earth's crust and cause the shaking that we feel during an earthquake. An EQ occurs when plates grind and scrape against each other. In California there are two plates the Pacific Plate and the North American Plate. The Pacific Plate consists of most of the Pacific Ocean floor and the California Coast line. The North American Plate comprises most the North American Continent and parts of the Atlantic Ocean floor. These primary boundary between these two plates is the San Andreas Fault. The San Andreas Fault is more than 650 miles long and extends to depths of at least 10 miles. Many other smaller faults like the Hayward (Northern California) and the San Jacinto (Southern California) branch from and join the San Andreas Fault Zone. The Pacific Plate grinds northwestward past the North American Plate at a rate of about two inches per year. Parts of the San Andreas Fault system adapt to this movement by constant "creep" resulting in many tiny shocks and a few moderate earth tremors. In other areas where creep is NOT constant, strain can build up for hundreds of years, producing great EQs when it finally releases.
Q: Can we cause earthquakes? Is there any way to prevent earthquakes?
Ans: Earthquakes induced by human activity have been documented in a few locations in the United States, Japan, and Canada. The cause was injection of fluids into deep wells for waste disposal and secondary recovery of oil, and the use of reservoirs for water supplies. Most of these earthquakes were minor. The largest and most widely known resulted from fluid injection at the Rocky Mountain Arsenal near Denver, Colorado. In 1967, an earthquake of magnitude 5.5 followed a series of smaller earthquakes. Injection had been discontinued at the site in the previous year once the link between the fluid injection and the earlier series of earthquakes was established. (Nicholson, Craig and Wesson, R.L., 1990, Earthquake Hazard Associated with Deep Well Injection--A Report to the U.S. Environmental Protection Agency: U.S. Geological Survey Bulletin 1951, 74 p.) Other human activities, even nuclear detonations, have not been linked to earthquake activity. Energy from nuclear blasts dissipates quickly along the Earth's surface. Earthquakes are part of a global tectonic process that generally occurs well beyond the influence or control of humans. The focus (point of origin) of earthquakes is typically tens to hundreds of miles underground. The scale and force necessary to produce earthquakes are well beyond our daily lives. We cannot prevent earthquakes; however, we can significantly mitigate their effects by identifying hazards, building safer structures, and providing education on earthquake safety.
Q: What do we know about the interior of the Earth?
Five billion years ago the Earth was formed by a massive conglomeration of space materials. The heat energy released by this event melted the entire planet, and it is still cooling off today. Denser materials like iron (Fe) sank into the core of the Earth, while lighter silicates (Si), other oxygen (O) compounds, and water rose near the surface. The earth is divided into four main layers: the inner core, outer core, mantle, and crust. The core is composed mostly of iron (Fe) and is so hot that the outer core is molten, with about 10% sulfur (S). The inner core is under such extreme pressure that it remains solid. Most of the Earth's mass is in the mantle, which is composed of iron (Fe), magnesium (Mg), aluminum (Al), silicon (Si), and oxygen (O) silicate compounds. At over 1000 degrees C, the mantle is solid but can deform slowly in a plastic manner. The crust is much thinner than any of the other layers, and is composed of the least dense calcium (Ca) and sodium (Na) aluminum-silicate minerals. Being relatively cold, the crust is rocky and brittle, so it can fracture in earthquakes. (Univ. of Nevada).
Q: What are plate tectonics?
Ans: Plate tectonics is the continual slow movement of the tectonic plates, the outermost part of the earth. This motion is what causes earthquakes and volcanoes and has created most of the spectacular scenery around the world.
Q: What is a fault and what are the different types?
Ans: A fault is a fracture or zone of fractures between two blocks of rock. Faults allow the blocks to move relative to each other. This movement may occur rapidly, in the form of an earthquake - or may occur slowly, in the form of creep. Faults may range in length from a few millimeters to thousands of kilometers. Most faults produce repeated displacements over geologic time. During an earthquake, the rock on one side of the fault suddenly slips with respect to the other. The fault surface can be horizontal or vertical or some arbitrary angle in between.
Earth scientists use the angle of the fault with respect to the surface (known as the dip) and the direction of slip along the fault to classify faults. Faults which move along the direction of the dip plane are dip-slip faults and described as either normal or reverse, depending on their motion. Faults that move horizontally are known as strike-slip faults and are classified as either right-lateral or left-lateral. Faults, which show both dip-slip and strike-slip motion are known as oblique-slip faults.
The following definitions are adapted from The Earth by Press and Siever.
Normal fault- a dip-slip fault in which the block above the fault has moved downward relative to the block below. This type of faulting occurs in response to extension and is often observed in the Western United States Basin and Range Province and along oceanic ridge systems.
Thrust fault- a dip-slip fault in which the upper block, above the fault plane, moves up and over the lower block. This type of faulting is common in areas of compression, such as regions where one plate is being sub ducted under another as in Japan. When the dip angle is shallow, a reverse fault is often described as a thrust fault.
Strike-slip fault - a fault on which the two blocks slide past one another. The San Andreas Fault is an example of a right lateral fault.
A left-lateral strike-slip fault is one on which the displacement of the far block is to the left when viewed from either side.
A right-lateral strike-slip fault is one on which the displacement of the far block is to the right when viewed from either side.
Q: At what depth do earthquakes occur?
Ans: Earthquakes occur in the crust or upper mantle, which ranges from the earth's surface to about 800 kilometers deep (about 500 miles).
Q: What is "surface rupture" in an earthquake?
Ans: Surface rupture occurs when movement on a fault deep within the earth breaks through to the surface. NOT ALL earthquakes result in surface rupture.
Q: What is the relationship between faults and earthquakes? What happens to a fault when an earthquake occurs?
Ans: Earthquakes occur on faults - strike-slip earthquakes occur on strike-slip faults, normal earthquakes occur on normal faults, and thrust earthquakes occur on thrust or reverse faults. When an earthquake occurs on one of these faults, the rock on one side of the fault slips with respect to the other. The fault surface can be vertical, horizontal, or at some angle to the surface of the earth. The slip direction can also be at any angle.
Q: How do we know a fault exists?
Q: Where can I go to see the/a fault?
Ans: The closest fault depends on where you live. Some earthquakes produce spectacular fault scarps, and others are completely buried beneath the surface. Sometimes you may not even know that you are looking at a fault scarp.
Q: What does an earthquake feel like?
Ans: Generally, during an earthquake you first will feel a swaying or small jerking motion, then a slight pause, followed by a more intense rolling or jerking motion. The duration of the shaking you feel depends on the earthquake's magnitude, your distance from the epicenter, and the geology of the ground under your feet. Shaking at a site with soft sediments, for example, can last 3 times as long as shaking at a stable bedrock site such as one composed of granite. If the site is in a building, then the height of the building and type of material it is constructed from are also factors. For minor earthquakes, ground shaking usually lasts only a few seconds. Strong shaking from a major earthquake usually lasts less than one minute. For example, shaking in the 1989 magnitude 7.1 Loma Prieta (San Francisco) earthquake lasted 15 seconds; for the 1906 magnitude 8.3 San Francisco earthquake it lasted about 40 seconds. Shaking for the 1964 magnitude 9.2 Alaska earthquakes, however, lasted three minutes.
Q: Foreshocks, aftershocks - what is the difference?
Ans: "Foreshock" and "aftershock" are relative terms. Foreshocks are earthquakes, which precede larger earthquakes in the same location. Aftershocks are smaller earthquakes, which occur in the same general area during the days to years following a larger event or "mainshock", defined as within 1-2 fault lengths away and during the period of time before the background seismicity level has resumed. As a general rule, aftershocks represent minor readjustments along the portion of a fault that slipped at the time of the main shock. The frequency of these aftershocks decreases with time. Historically, deep earthquakes (>30km) are much less likely to be followed by aftershocks than shallow earthquakes. (Univ. of Washington).
Q: Two earthquakes occurred on the same day. Are they related?
Ans: Often, people wonder if an earthquake in Alaska may have triggered an earthquake in California; or if an earthquake in Chile is related to an earthquake that occurred a week later in Mexico. Over these distances, the answer is no. Even the Earth's rocky crust is not rigid enough to transfer stress fields efficiently over thousands of miles.
Q:Can you predict earthquakes?
Ans:No. Neither the USGS nor Caltech nor any other scientists have ever predicted a major earthquake. They do not know how, and they do not expect to know how any time in the near future. However based on scientific data, probabilities can be calculated for potential future earthquakes. For example, scientists estimate that over the next 30 years the probability of a major EQ occurring in the San Francisco Bay area is 67% and 60% in Southern California.
Q: Can animals predict earthquakes?
Ans:Changes in animal behavior can not be used to predict earthquakes. Even though there have been documented cases of unusual animal behavior prior to earthquakes, a reproducible connection between a specific behavior and the occurrence of an earthquake has not been made. Animals change their behavior for many reasons and given that an earthquake can shake millions of people, it is likely that a few of their pets will, by chance, be acting strangely before an earthquake.
Q: Can you prevent large earthquakes by making lots of small ones, or by "lubricating" the fault with water?
Ans: Seismologists have observed that for every magnitude 6 earthquake there are 10 of magnitude 5, 100 of magnitude 4, 1,000 of magnitude 3, and so forth as the events get smaller and smaller. This sounds like a lot of small earthquakes, but there are never enough small ones to eliminate the occasional large event. It would take 32 magnitudes 5's, 1000 magnitude 4's, 32,000 magnitude 3's to equal the energy of one magnitude 6 event. So, even though we always record many more small events than large ones, there are never enough to eliminate the need for the occasional large earthquake.
As for "lubricating" faults with water or some other substance, injecting high pressure fluids deep into the ground is known to be able to trigger earthquakes to occur sooner than would have been the case without the injection. However, this would be a dangerous pursuit in any populated area, as one might trigger a damaging earthquake.
Q: Can some people sense that an earthquake is about to happen? (Earthquake sensitive)?
Ans: There is no scientific explanation for the symptoms some people claim to have preceding an earthquake, and more often than not there is no earthquake following the symptoms.
Q: Is there earthquake weather?
Ans: In the 4th Century B.C., Aristotle proposed that earthquakes were caused by winds trapped in subterranean caves. Small tremors were thought to have been caused by air pushing on the cavern roofs, and large ones by the air breaking the surface. This theory lead to a belief in earthquake weather, that because a large amount of air was trapped underground, the weather would be hot and calm before an earthquake. A later theory stated that earthquakes occurred in calm, cloudy conditions, and were usually preceded by strong winds, fireballs, and meteors.
However, there is no connection between weather and earthquakes. They are the result of geologic processes within the earth and can happen in any weather and at any time during the year. Earthquakes originate miles underground. Wind, precipitation, temperature, and barometric pressure changes affect only the surface and shallow subsurface of the Earth. Earthquakes are focused at depths well out of the reach of weather, and the forces that cause earthquakes are much larger than the weather forces. Earthquakes occur in all types of weather, in all climate zones, in all seasons of the year, and at any time of day. Sometimes, we are asked: "Do earthquakes change the weather in any way? Earthquakes themselves do not cause weather to change. Earthquakes, however, are a part of global tectonics, a process that often changes the elevation of the land and its morphology. Tectonics can cause inland areas to become coastal or vice versa. Changes significant to alter the climate occur over millions of years, however, and after many earthquakes.
Q: Are there more earthquakes in the morning/in the evening/at a certain time of the month?
Ans: Earthquakes are equally as likely to occur at any time of the day or month or year. The factors that vary between the time of the day, month, or year do not affect the forces in the earth that cause earthquakes.
Q: Can the position of the moon or the planets affect seismicity?
Ans: The moon, sun, and other planets have an influence on the earth in the form of perturbations to the gravitational field. The relative amount of influence is proportional to the objects mass, and inversely proportional to the square of its distance from the earth. No significant correlations have been identified between the rate of earthquake occurrence and the semi-diurnal tides when using large earthquake catalogs. There have, however, been some small but significant correlations reported between the semi-diurnal tides and the rate of occurrence of aftershocks in some volcanic regions, such as Mammoth Lakes.
Q: Can the ground open up during an earthquake?
Ans: Shallow crevasses can form during earthquake induced landslides, lateral spreads, or other types of ground failures. Faults, however, do not open up during an earthquake. Movement occurs along the plane of a fault, not perpendicular to it. If faults opened up, no earthquake would occur because there would be no friction to lock them together.
Q: Why are we having so many earthquakes? Has earthquake activity been increasing? Does this mean a big one is going to hit? We haven't had any earthquakes in a long time; does this mean that the pressure is building up and there will be a big one?
Ans: Although it may seem that we are having more earthquakes, earthquakes of magnitude 7.0 or greater have remained fairly constant throughout this century and, according to our records; have actually seemed to decrease in recent years. A partial explanation may lie in the fact that in the last twenty years, we have definitely had an increase in the number of earthquakes we have been able to locate each year. This is because of the tremendous increase in the number of seismograph stations in the world and the many improvements in global communications. In 1931, there were about 350 stations operating in the world; today, there are more that 4,000 stations and the data now comes in rapidly from these stations by telex, computer and satellite. This increase in the number of stations and the more timely receipt of data has allowed us and other seismological centers to locate many small earthquakes which were undetected in earlier years, and we are able to locate earthquakes more rapidly. The NEIC now locates about 12,000 to 14,000 earthquakes each year or approximately 35 per day. Also, because of the improvements in communications and the increased interest in natural disasters, the public now learns about more earthquakes. According to long-term records (since about 1900), we expect about 18 major earthquakes (7.0 - 7.9) and one great earthquake (8.0 or above) in any given year. However, let us take a look at what has happened in the past 32 years, from 1969 through 2001, so far. Our records show that 1992, and 1995-1997 were the only years that we have reached or exceeded the long-term average number of major earthquakes since 1971. In 1970 and in 1971 we had 20 and 19 major earthquakes, respectively, but in other years, the total was in many cases well below the 18 per year, which we may expect based on the long-term average.
A temporal increase in earthquake activity does not mean that a large earthquake is about to happen. Similarly, quiescence, or the lack of seismicity, does not mean a large earthquake is going to happen.
Q: Do earthquakes cause volcanoes?
Ans: No, there are different earth processes responsible for volcanoes. Earthquakes may occur in an area before, during, and after a volcanic eruption, but they are the result of the active forces connected with the eruption, and not the cause of volcanic activity.
For detailed news update on the earthquake in the subcontinent, check out the following links. The links cover the information pertaining to death toll, rescue and relief operations, impact of political relations of India and Pakistan on the rescue and relief operation etc.