Highest Five

The disastrous earthquake that hit Haiti January 12, 2010 has affected an estimated 3 million people and is one of the most catastrophic natural disasters recorded. Here are some of the most notable natural disasters the human race has ever seen, a little about what causes them and the deadliest ones on record.

Earthquakes

Cause: Earthquakes are caused by the movement of tectonic plates (large plates of rock that make up the foundation of the earth’s crust and the shape of continents) on the surface of the earth. Tectonic plates are constantly moving, towards, away or past each other. An earthquake occurs when there is a disturbance in the movements of plates, especially where one plate is forced under another.

Deadliest Earthquake:The 1556 Shaanxi earthquake or Jiajing earthquake is the deadliest earthquake on record, killing approximately 830,000 people. More than 97 counties in the provinces of Shaanxi, Shanxi, Henan, Gansu, Hebei, Shandong, Hubei, Hunan, Jiangsu and Anhui were affected. An 840-kilometre (520 mi)-wide area was destroyed, and in some counties 60% of the population was killed.

Cyclones & Hurricanes

Cyclone

Hurricane

Cause:The terms “hurricane” and “typhoon” are regionally specific names for a strong “tropical cyclone”. A tropical cyclone is a storm system characterized by a low pressure center and numerous thunderstorms that produce strong winds and flooding rain. Cyclones develop over warm seas near the Equator. Air heated by the sun rises very swiftly, which creates areas of very low pressure. As the warm air rises, it becomes loaded with moisture which condenses into massive thunderclouds. Cool air rushes in to fill the void that is left, but because of the constant turning of the Earth on its axis, the air is bent inwards and then spirals upwards with great force. The swirling winds rotate faster and faster, forming a huge circle which can be up to 2,000 km across. At the centre of the storm is a calm, cloudless area called the eye, where there is no rain, and the winds are fairly light.

Deadliest Cyclone:The oldest and the worst cyclone on record is that of October 1737 which hit Calcutta and took a toll of 300,000 lives in the deltaic region. It was accompanied by a 12 metre high surge. A violent earthquake coinciding with this storm enhanced the destruction.

Avalanches

Cause: Major causes of avalanches are weather, snowfall, temperature, wind direction, snow pack conditions, slope angle, slope orientation, terrain, and vegetation. Avalanches only occur when the stress on the snow exceeds the shear, ductile, and tensile strength either within the snow pack or at the contact of the base of the snow pack with the ground or rock surface.

Deadliest Avalanche: The 1970 Ancash earthquake or Great Peruvian Earthquake was an undersea earthquake that occurred on May 31 of that year. Combined with a resultant landslide, it was the worst catastrophic natural disaster ever recorded in the history of Peru. The quake destabilized the northern wall of Mount Huascarán, causing a rock, ice and snow avalanche and burying the towns of Yungay and Ranrahirca. The avalanche started as a sliding mass of glacial ice and rock about 3,000 feet (910 m) wide and one mile (1.6 km) long. It advanced about 11 miles (18 km) to the village of Yungay at an average speed of more than 100 miles per hour. The reported death toll from the earthquake and avalanche totalled 74,194 people, although some estimates place it as high as 80,000.

Tornadoes

Cause:Tornadoes form in unusually violent thunderstorms when there is sufficient instability and wind shear present in the lower atmosphere. They are caused when a cloud of the right size precipitates rapidly releasing heat, which causes it to rise, and creates a vacuum under it. The warm moist air is forced upward (either by the heat of the sun, a cold front, or other weather disturbances). If the atmosphere is unstable strong upward currents called updrafts lift the air until water vapor condenses forming clouds and precipitation.

Deadliest Tornado: The deadliest tornado in world history was the Daultipur-Salturia Tornado in Bangladesh on April 26, 1989, which killed approximately 1,300 people. The tornado was estimated to be approximately one mile wide, and had a path that was about 50 miles long, through the poor areas and slums of Bangladesh. Approximately 80,000 people were left homeless by the storm, and 12,000 people were injured by the storm.

Tsunamis

Cause:A tsunami is a large ocean wave that is caused by sudden motion on the ocean floor. This sudden motion could be an earthquake, a powerful volcanic eruption, or an underwater landslide. The impact of a large meteorite could also cause a tsunami. Tsunamis travel across the open ocean at great speeds and build into large deadly waves in the shallow water of a shoreline.

Deadliest Tsunami:The earthquake that generated the great Indian Ocean tsunami of 2004 is estimated to have released the energy of 23,000 Hiroshima-type atomic bombs, according to the U.S. Geological Survey (USGS). By the end of the day more than 150,000 people were dead or missing and millions more were homeless in 11 countries, making it the most destructive tsunami in history.

Floods

Cause: Heavy rainfalls are one of the major causes of floods. Floods can be caused by the overflow of huge volumes of water, from rivers, lakes, oceans, heavy rains downpours, hurricanes, cyclones, or tsunamis or unexpected event such as dam breakages.
Deadliest Flood: Throughout history, floods have proven to be the deadliest natural disasters and China boasts 6 of the world’s top 10 deadliest floods and landslides of all time. The 1931 Central China floods are a series of floods that occurred during the Nanjing decade in the Republic of China era. It is generally considered the deadliest natural disaster ever recorded, and almost certainly the deadliest of the 20th century (when pandemics are discounted) and in China. The human casualties are estimated from 3.7 million to 4 million.

Sinkholes

Cause: A sinkhole is a large depression in the Earth’s surface, often shaped like a well or a funnel, that can be up to several miles in diameter. A crack in underground limestone is often the first step in the formation of a sinkhole. A sinkhole may also be caused by a dramatic event, such as the collapse of a cave roof. Most commonly, sinkholes occur in urban areas due to water main breaks or sewer collapses when old pipes give way.

Most Disastrous: Whole buildings have been sucked into sinkholes and on February of 2007 entire roads were knocked out and part of a poor Guatemala City neighborhood plummeted some 30 stories into the Earth. The reportedly 330-foot-deep (100-meter-deep) sinkhole swallowed about a dozen homes and claimed the lives of three people.

Landslides & Mudslides

Landslide

Mudslide

Cause: Landslides are caused by disturbances in the natural stability of a slope. They can happen after heavy rains, droughts, earthquakes or volcanic eruptions. Mudslides develop when water rapidly collects in the ground and results in a surge of water-soaked rock, earth and debris. Mudslides usually begin on steep slopes and can be triggered by natural disasters. Areas where wildfires or construction have destroyed vegetation on slopes are at high-risk landslides during and after heavy rains.

Deadliest Landslide:The Kansu landslide is the worst in recorded history. An earthquake near the Tibetan border was felt through some 30,000 square miles of western China. Thousands of peasants lived in cave dwellings, carved into the sides of 100-foot-high clay cliffs and hills framing the riverbanks. After the earthquake, these cliffs were sheared off along deep vertical faults and sent falling into river valleys, destroying more than 100 cities, countless villages, and killing more than 180,000.

Deadliest Mudslide :The 1999 Vargas tragedy was a disaster that struck the Vargas State of Venezuela in December 1999. The torrential rains and mudslides that followed on 14 December through 16 killed tens of thousands of people, destroyed thousands of homes, and led to the complete collapse of the state’s infrastructure. The disaster caused estimated damages of USD $1.79 to $3.5 billion. More than 8,000 homes were destroyed, displacing up to 75,000 people. The death toll was considered to be between 10,000 and 30,000 — the exact number of casualties is difficult to estimate as there were no reliable census data, especially about shanty towns and small communities that were completely wiped out; moreover, only some 1,000 bodies were recovered, with the rest swept to sea by the mud or buried in the landslides.

Volcanoes

Cause: Inside the earth’s core there is a red-hot liquid rock, called magma. Volcanoes happen when magma rises to the surface of the earth, which causes bubbles of gas to appear in it. This gas can cause pressure to build up in the mountain, and it eventually explodes. When the magma bursts out of the earth, it is called lava.
Deadliest Volcano:Mount Tambora’s 1815 eruption on the on the Sumbawa islands of Indonesia was the largest eruption since the Lake Taupo eruption in 180 CE. The death toll was at least 71,000 people (making it the most deadly eruption in history), 11,000–12,000 were killed directly by the eruption but long-term implications were even worse. Some estimates say another 82,000 perished as a result of agricultural and environmental devastation

Blizzards

Cause: Snow storms can be caused by a warm front colliding with a cold front. This creates a low pressure zone. When clouds in the low pressure zone are filled with ice crystals, there are chances for a major blizzard. Low pressure creates high powered winds, as the warmer air spirals into the low zone, and adds a lot of movement. Therefore if a low pressure zone gets lower, the winds speed up.
Deadliest Blizzard: The Great Blizzard of 1888 was one of the most severe blizzards in United States’ recorded history. The storm, referred to as the Great White Hurricane, paralyzed the East Coast from the Chesapeake Bay to Maine, as well as the Atlantic provinces of Canada. Over 400 people died from the storm and the ensuing cold, including 200 in New York City alone.

Wildfires

Cause: The four major natural causes of wildfire ignitions are lightning, volcanic eruption, sparks from rockfalls, and spontaneous combustion.However, many wildfires are attributed to human sources such as arson, discarded cigarettes, sparks from equipment and power line arcs.
Deadliest Wildfire: The October 8, 1871 Peshtigo Fire in Peshtigo, Wisconsin, is the conflagration that caused the death of 1,700 people, the most deaths by fire in United States history.  Having occurred on the same day as the more infamous Great Chicago Fire, the Peshtigo Fire is mostly forgotten.