In one minute an earthquake destroyed this city with the most extensive ground rupturing ever witnessed by mankind. Huge differences in the shaking of ground on sedimented rock versus bedrock gave geologists a new understanding of earthquake hazards. Up to 6000 people were killed and much of the damange was caused by secondary hazards such as broken gas lines and disrupted water supplies. Did you know that uncontrolled fires burnt in San Francisco for 4 days and 4 nights. These fires accounted for much of the aftermath and destruction caused by the earthquake.

Valdivia, Chile (1960)

This magnitude 9.5 earthquake is the strongest ever recorded. Severe ground shaking caused massive damage and generated a tsunami with waves as high as 38 feet. It caused hundreds of deaths in Chile, Hawaii, Japan and the Phillippines.

Tangshan, China (1976)

At least a quarter of a million people died in what was one of the most deadliest earthquakes of the 20th century. Centered in the Hebei Province, it occurred in the early hours of the morning lasting just 10-15 seconds. This short quake was followed by an intense aftershock just 16 hours later which contributed to much of the death toll.

Mexico City, Mexico (1985)

A magnitude 8.1 subduction zone earthquake devastated Mexico City in 1985 killing almost 9000 people. The epicenter of the quake was almost 220 miles offshore and despite this the damage was extensive. The city shook for almost 3-4 minutes with many areas especially those that were built on the silty sediments of Lake Texcoco take a big hit.

Kobe, Japan (1995)

This fierce subduction zone earthquake first struck near Awaji Island where the ground heaved up almost 9 feet. Seismic waves then propogated through the crust to Kobe (12 miles away). The damage caused was extensive making this one of the worlds most expensive disasters.

Faults are classified by the direction of movement between their opposing faces. These movements can occur slowly and continuously or in large sudden shifts that can deform or rupture the land surface. Either way it’s the direction of these movements that characterise the actual fault types and we’ll try to cover these below.

• Dip Slip Faults - These are faults where the major movement is vertical.
• Strike Slip Faults - These are faults where the major movement is horizontal.
• Oblique Faults - These are faults where them major movements are both horizontal and vertical.

Note that in the above we are referring to the major part of the movement as most fault lines always demonstrate some level of both vertical and horizontal movement but for definition purposes we’re really referring to the major movement of that fault. Lets continue and break the fault types down even more.

Types Of Dip Slip Faults

Within the dip slip fault category (major vertical movements at the fault line) there are two main fault types.

• Normal Fault - Here rocks on one side of the fault slump below the other side.
• Reverse Fault - Here rocks on one side of the fault get pushed up above those on the other side.
• Thrust Fault - This fault is extremely similar to the reverse fault except that it happens at lower angles causing a stacking of the rocks which ultimately leads to a thickening of the local crust.

Types Of Strike Slip Faults

Within the strike slip fault category (major horizontal movements at the fault line) there are two main fault types.

• Left Lateral Strike Slip Fault - Also known as a Sinistral fault here rocks on one side of the fault slide past each other in a horizontal movement. The left is determined by the direction of the displaced fault line. i.e. it would be on the right if you were walking towards it.
• Right Lateral Strike Slip Fault - Also known as a Dextral fault here rocks on one side of the fault slide past each other in a horizontal movement. The right is determined by the direction of the displaced fault line. i.e. it would be on the right if you were walking towards it.
• Transform Fault - This is a special type of strike slip fault because it happens to run at the bounday of a tectonic plate. Although most transform faults are found on the ocean floor, many of the more well known transform faults are on dry land. The San Andreas fault line is a classic example of a land based transform fault.

When these cracks or faults experience even the smallest movements they can end up rubbing or sliding against opposing rock faces causing severe stress to cause the sudden rumbles we know as earthquakes. This article will cover a few of the major fault lines that exist around the world.

Anatolian Fault (Turkey)

This major transform fault crosses Turkey from east to west just 12 miles south of Istanbul. It’s been the site of many high energy earthquakes, which during the 20th century alone has caused more than 50,000+ fatalities.

Andaman Fault (Andaman Sea)

This plate sits in the strait that separates Burma and Sumatra. In 2004 It ruptured along roughly 1000 miles of fault line producing a huge earthquake and Tsunami known as the great Sumatra Andaman earthquake. Not only was it an event of huge destruction (300,000 lives lost) but as a geological phenomenon it was the largest to happen in the past 40 years which was then followed by the second largest just three months later on March 28, 2005.

Dead Sea Fault Zone (Dead Sea)

This transform fault allows sliding between the Arabian and African plates and over the last 20 million years has moved 50 miles north of the western side creating the Dead Sea.

Denali Fault (Alaska, USA)

This long transform fault which goes from west to east under Alaska has slid an estimated 250 miles since the late Mesozoic era. In 2002 it produced a magnitude 7.9 earthquake.

Tanshan (HEBEI), China (1976)

Chinese villagers have long remembered 1976 as “the year of the curse”. On July 27th an earthquake with a magnitude of 7.8 on the richter scale struck China’s Tanshan region. The initial quake lasted for 10 seconds and featured aftershocks hitting as high as 8.2 on the richter scale. This was a devastating earthquake hitting a population of around 15 million and leaving casualty figures ranging from 500,000-800,000 dead.

Now despite scientists having a poor record in terms of predicting earthquakes the Tanshan incident was one event that benefitted greatly from an early prediction. Damage limitation is what it’s all about and scientist are certain that many more would’ve died if the area hadn’t received early warning from the State Seismological Bureau (SSB) Analysis and Prediction Department. The organization estimated that an earthquake would occur between mid-July and early August (1976). It took 60 people, including the esteemed official, Wang Chunging to warn the population and prepare for the disaster.

In all, there was 10 billion yen in total damage, and an estimated 85% of the buildings in Tanshan were destroyed. The Communist Party at the time of the incident turned down any international aid as the government wanted to be self reliant and not depend on Western funds.

Haiyuan County, China (1920)

Haiyuan (Ningxia) was victimized by a destructive quake that measured by today’s standards an 8.5 magnitude. This disaster occurred on December 16th and is often referred to as the Gensu earthquake (at the time, Ningxia was part of the Gensu province).

Landslides and ground cracks ripped through the epicenter and between 200,000-240,000 people died with tens of thousands more injured. Another chinese earthquake and the fourth deadliest quake on record. 3

San Francisco, USA (1989)

America’s national pastime was briefly interrupted in October 1989 by an earthquake which is amazing because it was captured on live television. The San Francisco Giants were playing against the Chicago Cubs when Candlestick Park shook. Television cameras filmed the chaos and for about ten seconds, people tumbled to the ground, debris fell from buildings and everyday life in San Francisco came to a halt.

In total 80 people were killed and hundreds severly injured. Despite the death toll being tiny in comparison to the previously mentioned Chinese quakes, we decided to include this quake in our list due to the sheer cost of damage and disruption caused by this quake. Totals reached hundreds of millions of dollars and it became one of America’s biggest earthquakes of recent times.

For San Francisco the quake had done it’s damage and to top things off after the world series was delayed for two weeks, they eventually got swept by the Oakland Athletics 4-0.

Sichuan Province, CHINA (2008)

China’s Communist government prepared for the Beijing Olympics. It spent over $10 billion building up security, celebration decorations, television coverage and constructing their Olympic Village. All of that changed on May 12th when the Sichuan province was hit with a 7.9 magnitude quake.

Over 69,000 were killed and thousands more injured, another 18,222 were listed as missing or presumed dead, and about five million people in total were made homeless. In total the disaster affected 15 million people but despite this the Chinese were able to open the Summer Olympics on schedule.

Indian Ocean (2004)

A massive earthquake ripped through Southeast Asia, when the Indian Oceans floor cracked. The eruption created a 100-ft. tsunami (tidal wave) that swept through Sri Lanka, Thailand, Laos and Indonesia. It destroyed beaches, resorts and coastal towns with thousands of civilians, including western tourists killed and drowned by its destruction. Over 240,000 people died and billions of dollars went into rebuilding.

It’s not a pretty picture but there are things you can do to remain prepared and ready if it ever happened to you. This article will focus on some basic tips and reminders of what to do if you’re experiencing a major earthquake.

Tips Before An Earthquake (Preparation)

Sure scientists can’t predict earthquakes but we can certainly anticipate them, certain regions are clearly more prone to the phenomena, so if you’re living in one, be sure to complete the following preparation tips.

• Talk to your family about earthquake safety, make sure they know what to do if one happens
• Know your room’s strong points, such as hiding under foundations, doorways, tables and beds
• Don’t put heavy shelves or other furniture above your bed or place of sleep
• Stock up emergency supplies. Pick up a battery-operated radio, a flashlight, first-aid kit, bottled water, blankets, food and supplies for two to three weeks
• Pick up an earthquake medical/saftey kit (Yes they actually do exist)

Tips If You’re Inside

If you’re indoors when the quake hits, follow these simple steps to increase your chances of survival.

• Always stay indoors
• Move to a safe location in the room, duck under a strong desk, table, doorway or along an interior wall. First and foremost, protect yourself from falling objects
• Put on some shoes, it will protect your feet if things like glass and other materials have spread over the floor
• If you’re cooking, stop immediately, turn off the stove and take cover
• Turn off the gas, electricity and water supplies to your building

Tips If You’re Outside

• Stay in an open area where falling objects won’t strike you
• Duck into a ditch and keep away from buildings, power lines and trees
• If you’re driving, slow down to a crawl and stay in the center of the road. Don’t stop under bridges, overpasses, trees, or large signs.

Tips For After The Earthquake

• Check for injuries and try to get immediate medical care. Keeping the people around you safe is your main priority.
• Check for damage, if your dwelling is badly damaged, leave it until a safety inspector comes and allows you back in.
• Assist others who may be injured, during an earthquake everyone’s got to look out for each other