Earthquake, Chile

On the morning of 27th February 2010, a massive earthquake of 8.8 on the Richter scale hit the coast of Chile for 90 seconds at 6.34am , causing buildings to collapse and triggering a tsunami.

Coastal towns suffered fatal double blows, as tsunamis came crashing onto their shores. A tsunami warning was extended across 53 countries, including most of Central and South America and even Australia and Antartica. The tsunami has caused extensive damage to a number of islands, and travelled across the ocean at a shocking speed of hundreds of kilometers per hour. However, the warning at one of the affected islands, Hawaii, was lifted. 1m high waves hit the shores, but no damage were reported. Although islands like Hawaii were not badly affected, the giant waves are known to affect islands like Juan Fernandez islands, causing serious damage.

The quake hit near the town of Maule, 325km southwest of Santiago, at a depth of 25km underground. The epicentre was just 115km from Concepcion, Chile’s second-largest city.

The giant quake caused widespread damage, destroying buildings, bridges and roads in many areas, causing huge cracks in roads and bridges. Water, phone lines and electricity were cut, thus worsening the already bad conditions. This renders rescue efforts hard to be carried out, not to mention the dangerous conditions for rescuers to carry out their missions.

8 aftershocks were recorded, largest of which has a magnitude of 6.9. Chile is highly vulnerable to earthquakes due to its location. It is situated on the infamous Pacific “Ring of Fire”, on the edge of the Pacific and South American plates. It has suffered many earthquakes, the biggest of which is the 1960 earthquake, with magnitude 9.5, which struck the city of Valdivia, killing 1655 people.

The initial official death toll of the 2010 Chile earthquake was put at 800 was lowered to 528, reason given was that the initial death toll included those who were displaced. And also, some of the people who were thought to be killed by the earthquake turned out to be alive.

More than half a million homes were destroyed, resulting in about 2 million people homeless, forcing them to live on the streets. With the emergency situation, major supermarkets were ordered to give away essential food and water supplies to the affected Chileans.

More than half a million homes were destroyed, resulting in about 2 million people homeless, forcing them to live on the streets. The emergency situation required major supermarkets to give away essential supplies such as food and water.

Relief efforts were also provided by many countries and organisations in the form of emergency supplies. The UN World Food Program (WFP) delivered food aids, one of which is in the form of high-energy biscuits enough to feed 35,000 children for 5 days. World Vision has also organized operations to aid the relief efforts by supplying necessary high-priority supplies for the survivors in the form of food, water, water tanks, water purification tablets, cooking items, hygiene kits, disposable nappies, candles, batteries, flashlights, blankets, sleeping bags and lanterns, especially in the hard-hit areas of Concepcion and Santiago.
Financial assistance is also heavily required for rebuilding efforts. Japan gave 3 million US dollars in emergency grant aid to Chile, following a formal request from Chilean President Michelle Bachelet for international assistance. These forms of financial aid is crucial in the rebuilding of the country after the vicious earthquake had hit Chile.

However, other then aid in emergency supplies, psychosocial and psychological aid is necessary for the survivors, especially the children. The earthquake and aftershocks brought about a negative emotional impact on the children, and requires serious and immediate attention and concern.

With the different relief efforts and aids, Chile has hope of a bright future ahead, however this rebuilding will need time of about a few years.

By Nur Farizah Bte ROslan (10S01)

New Orleans - Hurricane Katrina

Background

On August 28th, 2005, Hurricane Katrina hit the eastern coast of New Orleans in United States. By August 31st, 2005, 80% of New Orleans was flooded with some parts under 15 feet (4.5 m) of water. More than 1,800 people lost their lives, and more than $81 billion dollars in damages occurred.
Hurricane Katrina was the sixth strongest recorded Atlantic hurricanes ever, and was amongst the five deadliest hurricanes that ever occurred in the US history.

Effects

Before the Katrina attack,

Max Mayfield, the director of the National Hurricane Center, telephoned New Orleans Mayor, Ray Nagin, on the night of August 27th to express his extreme concern, and on the morning of August 28th, made a video call to U.S. President, George W. Bush, about the severity of the storm. Many New Orleans residents secured their belongings and prepared for evacuation immediately as Mayor Nagin issued the first ever mandatory evacuation of New Orleans.
About 1 million people managed to flee New Orleans and its surrounding suburbs by the second hit of Katrina the next morning.

After the Katrina attack,

• Many telephones, including most cell phones, and Internet access were not working due to line breakages, destruction of base stations, and power failures, and all local television stations were disrupted. This made coordination of rescue and the telecasting of the disaster difficult.
• Most of the major roads traveling into and out of the city were damaged and this toughened rescue efforts. Louis Armstrong New Orleans International Airport was closed before the Katrina attack but was reopened for rescue work because there was no flooding in airplane movement areas and inside the building itself. The renowned Superdome was no longer safe for the people seeking shelter in it too.
• The levee system built by the US Army Corps of Engineers was severed damaged by Katrina and it was said to be the worst engineering disaster in US history. The US Army Corps of Engineers admitted that faulty design specifications, incomplete sections, and substandard construction of levee segments, contributed to the damage done to New Orleans by Hurricane Katrina and two thirds of the flooding in the city would have been avoided if the levees held.
• Death toll of 1,836 was resulted and dead bodies were found everywhere in the city; most survivals lost their loved ones.
• Toll on America’s economy (E.g. New Orleans was pro active in oil refining and this form of income for America ceased periodically after the Katrina attack).
• Unstable homes, unclean water and insufficient food for the survivals as it took time to repair the damage.
• Increased crime rates as survivals looted to fight for necessities and non-necessities.
• International criticism on US’ lack of leadership to minimise the impacts of Katrina and mismanagement regarding the relief efforts of the attack.

Measures

• Non-governmental organizations like the American Red Cross rendered financial aid and helped raised US$4.25 billion to help the victims.
• US Army Corps of Engineers proceeded with the reconstruction of levees, with new considerations of the new levees locations and further modification to be made.

So,
a natural disaster could happen anytime and anywhere. It could possibly happen just where we live tomorrow. Hence, it is very important for the government to always take precautions and ensure the national facilities are working in good conditions so as to defend the country with preparedness when need be and the citizens should also be prepared to stay united in terms of a crisis. This is all we can control and we should make good use of this abilityto do so and this would minimize the impacts of a natural disaster.

By Cheryl Mun (10S01)

Heatwaves in Australia

Heatwaves in Australia

Australia has a long history of heatwaves. The worst recorded heatwave was in 1939 when 438 people died. This heatwave affected South Australia, Victoria and New South Wales.
Heatwaves have accounted for more deaths in Australia than any other climatic event. Some of the worst heatwaves on record are below:

-January 1896 - 437 people died
-January 1908 - 246 people died
-February 1921 - 147 people died
-January 1927 - 130 people died
-January 1939 - 438 people died
-February 1959 - 105 people died
-January 1973 - 26 people died
-February 1981 - 15 people died
-February 1993 - 17 people died
-February 2004 – 12 people died.

It’s getting hot in here!

The highest temperature in Australia was 50.7°C at Oodnadatta in South Australia in 1960.
Marble Bar in Western Australia holds the record for the longest days in a row when the temperature was above 37.8°C for 160 days in 1923-24.
The hottest day in Sydney was set in 1939 when it got to 45.3°C.

Exceptional Australian Heat Wave

In early February 2009, residents of southeastern Australia were cringing at their weather forecasts, as predictions of temperatures above 40 degrees Celsius (104 degrees Fahrenheit) meant that a blistering heat wave was continuing.

This map of Australia shows how the land surface temperature from January 25 to February 1 compared to the average mid-summer temperatures the continent experienced between 2000-2008. Places where temperatures were warmer than average are red, places experiencing near-normal temperatures are white, and places where temperatures were cooler than average are blue. The data were collected by the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite.

By: Marie Tan 10S01

Eyjafjallajökull Iceland Volcanic Eruption 2010

Effects:

• Flights cancelled (European Airways affected) Air France lost about US$300 million in revenue.
• Airlines affected for 9 days.
• More than 63,000 flights had been cancelled in 23 European countries, businessmen who need to get to another country find themselves stranded for at least 3 days, as trains and rental cars are fully booked for days.
• Health risk: breathing in ash or poisonous gases like sulfur dioxide, may develop complications especially for those with existing respiratory problems.
• No aeroplanes to transport food. Agricultural workers will lose income.
• Other forms of transport like companies that rent out vehicles and trains and ferries will earn more revenue,
• Hotel trade will also make more money as people are staying longer. However, some hotels will also lose business because people have are not able to travel there.
• In those hotels, there are more room vacancies and many employees are now redundant.
• The impact on smaller businesses is more severe. Companies that depend on imports from other countries, will find themselves out of stock of certain items. For example, florists who get flowers from another country.
• The stocks have fallen due to flights being cancelled and airlines losing money.
• Celebrities may have to cancel performances because they are not able to get to their destination.

Measures taken to solve problem of people stranded in foreign countries

• Deploying the Royal Navy, cruise ships and commercial shipping to transport passengers to the UK if the crisis worsens.
• Using Spain, which is not yet affected by the eruption, as a dropping-off point for stranded air passengers before continuing their journey by train, coach or boat.
• British consulate officials visiting key airports worldwide to advise passengers of their rights, including food and accommodation from EU-registered carriers.

As you can see from the effects, just one volcano can cause a lot of problems to its surrounding countries and affect the world (stock market). This shows the interconnectedness of this world. Singapore is considered lucky, as it has once again not a direct victim of this eruption, hence the impact on our economy is minimal.

The European countries have been criticized of being unprepared for this emergency, as the previous eruption of Iceland happened in the 1810s. That time, solutions were maybe not recorded, and there was probably not much interconnectedness in the world. However, the problem of being stranded could be alleviated, as in 2001, September 11, the same situation happened. The problem cannot be avoided, as there is still speculation whether the volcano will still erupt, making air travel impossible. In 911, the duration of the attack is much shorter than the volcanic eruption and thus, people were stranded for a shorter period of time.

By Angus Ng (10S01)

Aceh Tsunami

On the 26th December 2004, Banda Aceh, Indonesia, was hit with a Tsunami with wave heights as high as 30 metres. It was one of the deadliest natural disaster ever happening in history. The Tsunami has killed about 230 000 people and made 500 000 others homeless. Aceh was one of the hardest-hit areas by the tsunami caused by the Indian Ocean earthquake of magnitude of 9.3 according to the Pacific Tsunami Warning Centre. This earthquake is the second largest earthquake ever recorded by a seismograph.

The earthquake which had resulted in the tsunami, was caused by the tectonic movement of the Indian and Burma plate. At these plate boundaries, 2 activities happened. First was the subducting of the Indian plate under the Burma plate. Second was the faulting of both plates where both slides past each other, one moving upwards and the other moving downwards, causing a large displacement in height of the sea water. As a result, tsunami waves were formed due to the displacement of about 30 km3 of water.

Aceh was not only the place being hit with the Tsunami. Countries like India and Sri Lanka was also affected. Others that are known are affected mostly by the earthquake.

Due to the tsunami, Aceh's infrastructure was greatly affected. Most of its buildings are destroyed leaving their citizens homeless and unaided. Hence, many neighbouring countries have come forward to help the country in providing the daily necessities and health care to the people.

Economically, the country was affected as the coastal fishing communities and fisherfolks were unable to generate their only way of income. Environmentally, pollutions happened and these affected the ecosystem in some ways. Tourism in the country has also declined drastically eversince the disaster.

Rebuilding and recoveringf of the city has taken a long time as the country has lost about US$4.5 billion. t has received monetary aid from the World Bank to rebuild it's city. Aceh has also decided to build a tsunami detecting system so that the country will be more prepared when another tsunami is bound to happen in the future. The country believes that another tsunami may happen in the future since such natural disasters are more prone to happen these few years.

The tsunami that happened in Aceh has made the world realise how important it is to be ever ready for such natural disasters that can occur anytime without any warning. Therefore, it is advisable to install a detecting system than to lose many innocent lives due to such disasters in the future.

By Nurul Atiqah (10S01)

Typhoons and Cyclones (Indonesia) #3

Safety Tips

Outdoor Safety Tips:
• Leave low-lying areas.
• Moor your boat securely or evacuate it.
• Protect your windows with boards, shutters, or tape.
• If at the Beach, watch for waves coming inland.
• Secure outdoor objects or bring them indoors.
• Fuel your car.
• Save several days' water supply.
• Stay at home if it is sturdy and on high ground.
• Leave mobile homes for more substantial shelter.
• Stay indoors during a hurricane.

Indoor Safety:
• Listen for storm advisories and warnings on the radio
• Check your supplies, camping equipment, and emergency cooking equipment.
• If in a public building, get away from glass
• If driving or riding in a car, get out, and seek cover under a freeway overpass, doorway or stairwell.
• Avoid power lines, trees, buildings and windows.

After the Cyclone Safety Tips:
• Avoid driving if possible. If driving is necessary, drive with caution.
• Stay away from riverbanks and streams.
• Beware of loose or dangling electrical wires.

Typhoons and Cyclones (Indonesia) #2

Typhoons and Cyclones (Indonesia) #1

Overview

Cyclones, and Typhoons all have the same characteristics, but they have different names where they appear:
• Cyclones- Indian Ocean
• Typhoons- Pacific Ocean

Typhoons can hit the Islands of the Indonesia between September and December, and can cause rainstorms and heavy winds. However, not every Typhoon that hits Indonesia is a strong one, and in some years only a few Typhoons occur during the tropical storm season.

Typhoons and cyclones are two of nature’s most powerful forces. They are all tropical storms whose winds reach around 74 miles per hour or even more. Their wind blows in a spiral direction around a relatively calm area known as “The Eye”. The eye is usually 20 to 30 miles wide. The most violent activity takes place in the area immediately around the eye, called “The Eyewall”. As the hurricane approaches, the sky begins to darken, and the wind gets stronger. As it nears lands, it may bring torrential rain, storm surges, and very high winds. One hurricane can last for more than 2 weeks in open waters. The heavy rain brought by a hurricane not only threatens coastal areas, but it also hits areas hundreds of miles inland. In some cases, flooding occurs days after a storm actually hits shore.

Tsunami (Indonesia) #2

Case Study: Boxing Day Tsunami (26th December 2004)



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).

The epicenter of the 9.0 magnitude quake was under the Indian Ocean near the west coast of the Indonesian island of Sumatra, according to the USGS, which monitors earthquakes worldwide. The violent movement of sections of the Earth's crust, known as tectonic plates, displaced an enormous amount of water, sending powerful shock waves in every direction.

The earthquake was the result of the sliding of the portion of the Earth's crust known as the India plate under the section called the Burma plate. The process has been going on for millennia, one plate pushing against the other until something has to give.

The result on December 26 was a rupture the USGS estimates was more than 600 miles (1,000 kilometers) long, displacing the seafloor above the rupture by perhaps 10 yards (about 10 meters) horizontally and several yards vertically. That doesn't sound like much, but the trillions of tons of rock that were moved along hundreds of miles caused the planet to shudder with the largest magnitude earthquake in 40 years.

Above the disturbed seafloor the great volume of the ocean was displaced along the line of the rupture, creating one of nature's most deadly phenomena: a tsunami.
Within hours killer waves radiating from the earthquake zone slammed into the coastline of 11 Indian Ocean countries, snatching people out to sea, drowning others in their homes or on beaches, and demolishing property from Africa to Thailand.



Many coastal areas in the Indian Ocean had almost no warning of the approaching tsunami. The only sign of the tsunami announcing its arrival in several places was in the form of a rapidly receding ocean. Many reports quoted survivors saying how they had never seen the sea withdraw such a distance, exposing seafloor never seen before, stranding fish and boats on the sand. Tragically the novelty of the sight apparently stoked the curiosity of the people who ran out onto the exposed seafloor. Tourists in Thailand were seen wandering around photographing the scene.

Some people did not know that the tsunami is a series of waves. Once the first wave had gone, they thought it was safe to go down to the beach.

Survivors of the Indian Ocean tsunami reported that the sea surged out as fast and as powerfully as it came ashore. Many people who had survived the wall of water rushing inland were seen being swept out to sea when the ocean retreated.

Serious damages were done to infrastructures. The tourist flow of the affected countries took a dip and recovery was expected only in two to three years’ time. This resulted in a significant drop in tourist revenue for these countries.



Fishing and shipping industries in the Tsunami-hit countries were greatly affected. Many of the fishing boats and equipments were destroyed resulting in loss of jobs.

Salt water infiltration and eutrophication resulted in ecosystems being damaged. Non-biodegradable waste and poisonous substances such as lithium and arsenic were released into the sea and led to marine life being disrupted.



The people’s psychological states were affected drastically due to the grief of losing loved ones. Many of them were traumatized and could not get back on their feet after this disaster.

Tsunami (Indonesia) #1

Overview

An earthquake generates a tsunami if it is of sufficient force and there is violent movement of the earth causing substantial and sudden displacement of a massive amount of water.

A tsunami is a series of waves, and the first wave may not be the most dangerous. A tsunami, also known as "wave train", may come as surges five minutes to an hour apart. The cycle may be marked by repeated retreat and advance of the ocean.



Tsunami waves can be very long (as much as 60 miles, or 100 kilometers) and be as far as one hour apart. They are able to cross entire oceans without great loss of energy.

Geological features such as reefs, bays, river entrances, and undersea formations may dissipate the energy of a tsunami. In some places a tsunami may cause the sea to rise vertically only a few inches or feet. In other places tsunamis have been known to surge vertically as high as 100 feet (30 meters). Most tsunamis cause the sea to rise no more than 10 feet (3 meters).

Tsunamis do not necessarily make their final approach to land as a series of giant breaking waves. They may be more like a very rapidly rising tide. This may be accompanied by much underwater turbulence, sucking people under and tossing heavy objects around. Entire beaches have been stripped away by tsunamis.

Warning Signs:
An earthquake is a natural tsunami warning. If you feel a strong quake do not stay in a place where you are exposed to a tsunami. If you hear of an earthquake be aware of the possibility of a tsunami and listen to the radio or television for additional information. Remember that an earthquake can trigger killer waves thousands of miles across the ocean many hours after the event generated a tsunami.

Witnesses have reported that an approaching tsunami is sometimes preceded by a noticeable fall or rise in the water level. If you see the ocean receding unusually rapidly or far it's a good sign that a big wave is on its way. Go to high ground immediately.

Because tsunamis can approach the shore as fast as 100 miles per hour (160 kilometers per hour) it is often too late to get away if you see one. An approaching tsunami is not something to be admired unless you are safely on high ground.


Strategies applied (In General)

Many Insurance Companies are still reluctant or slow to promote earthquake insurance in Indonesia, no doubt mainly because Insurers recognize it as a risk.
A characteristic feature of natural catastrophes is their low occurrence frequency but high loss impact. In view of low probability, the general cultural attitude in many Asian Countries, particularly in Indonesia, is that most people tend to ignore the risk of natural perils. This attitude unfortunately remains unchanged even after the earthquake and tsunami in Aceh.


There are at least 3 (three) alternatives to promote catastrophe risk insurance:
1.As a standard peril included within a fire policy
2.As an additional cover in conjunction with a fire policy at additional premium or as a separate policy on its own
3.Under a Government supported insurance scheme, often in a compulsory manner, where Government intervene to increase penetration of Catastrophe insurance.

Programmes in plan:
1.Disaster Management Plan

Set up Disaster Preparedness Plan and Contingency Plan

2.Public Awareness

Information, Education, Training and Drilling

3.Risk Assessment

Hazard, Vulnerability and Risk mapping at local level

4.Early Warning Systems

Monitoring, Analysis, Warning and Dissemination

5.Operation Centers

Set up Operation Centers in National, Provincial and Local level

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Earthquakes (Indonesia) #2

Case Study: 30th September 2009, Padang


Padang, the capital of Indonesia's West Sumatra province, sits on one of the world's most active fault lines along the "Ring of Fire" where the Indo-Australia plate grinds against the Eurasia plate to create regular tremors and sometimes quakes.



At least 1100 people were killed, 2181 were injured and thousands are still unaccounted for in the Padang area. More than 2650 buildings have been damaged in the area and landslides have disrupted power and communications. Felt (VII) at Padang. Widely felt throughout Sumatra and Java, Indonesia, Malaysia, Singapore and Thailand. A small local tsunami with wave heights of 27 centimeters (amplitude measured relative to normal sea level) was generated.



"We don't know the identity of the victims yet, it's night-time now so it's dark. People are trapped, hotels have collapsed, schools have collapsed, houses have collapsed and electricity has been cut off," Vice-President Jusuf Kalla said on the day of the earthquake, quoted by AFP news agency.

An unnamed witness told Reuters there was "extreme panic" in the city, with bridges down and flooding caused by broken water pipes.




The earthquake struck at 1716 local time (1016 GMT) some 85km under the sea, north-west of Padang, the US Geological Survey said.



The quake was along the same fault line that spawned the 2004 Asian tsunami that killed more than 230,000 people in a dozen countries.



"Hundreds of houses have been damaged along the road. There are some fires, bridges are cut and there is extreme panic here," said a Reuters witness in the city, who also said broken water pipes had triggered flooding.



His mobile phone was then cut off and officials said power had been severed in the city. A resident called Adi later told Indonesia's Metro Television there was devastation around him.
"For now I can't see dead bodies, just collapsed houses. Some half destroyed, others completely. People are standing around too scared to go back inside. They fear a tsunami," said Adi.
"No help has arrived yet. I can see small children standing around carrying blankets. Some people are looking for relatives but all the lights have gone out completely."



Geologists have long warned that Padang could one day be completely destroyed by an earthquake because of its location.

"Padang sits right in front of the area with the greatest potential for an 8.9 magnitude earthquake," said Danny Hilman Natawidjaja, a geologist at the Indonesian Science Institute, in February.

"The entire city could drown" in a tsunami triggered by such a quake, he warned.

Earthquake (Indonesia) #1

Overview

In the wake of devastating - and unconnected - earthquakes and tsunamis in Indonesia and Samoa, the BBC News website looks at the so-called Pacific "Ring of Fire" - the zone of major seismic activity which has one of the world's most active fault lines.



Circling the Pacific Basin, on the bottom of the sea bed, lie a dramatic series of volcanic arcs and oceanic trenches.
The zone - known as the "Ring of Fire" - is notorious for frequent earthquakes and volcanic eruptions, and coincides with the edges of one of the world's main tectonic plates.

At the edges, one of three things may occur:
• The plates can be moving away from each other, leaving space for new ocean floor
• Some plates are moving towards each other, causing one to submerge beneath the other
• Other boundaries slide past each other without much disturbance.

Parts of the plate boundary that slide past one another in opposite directions - such as the San Andreas Fault - cause minor earthquakes.

But where one oceanic plate collides with and is forced deep into the Earth's interior, the subsumed plate encounters high temperatures and pressures that partially melt solid rock.

Some of this newly-formed magma rises to the Earth's surface and erupts, forming chains of violent volcanoes - like the Ring of Fire.

These narrow plate-boundary sites, known as subduction zones, are also associated with the formation of deep ocean trenches and big earthquakes.

When there is an earthquake under the sea, one side of the ocean floor suddenly drops downward, beneath the top edge of the subducting plate.

The resulting vertical fault will generate a tsunami - much as a wave machine in a swimming pool will generate one.

Strategies applied (In General)

The Indonesian Insurance Association has successfully introduced the
Indonesian Standard Earthquake Insurance Policy to the market. The policy must be used by all general insurance companies operating in Indonesia for the purpose of uniformity.

Policy Coverage
The policy covers loss and/or damage to the insured’s property with or without business interruption as a result of:
• Earthquake shock
• Fire following earthquake
• Volcanic eruption and
• Tsunami

Landslides (Indonesia) #3

Case Study 2: Rain-triggered Landslides

Torrential rains triggered a series of landslides on Indonesia's Sulawesi island, killing at least 14 residents and burying many more, a local official said Monday.

The downpours sent a mass of mud slamming into about 20 houses in the outskirts of the town of Palopo, South Sulawesi province, Mayor Pateddungi Tenri Ajeng said Monday.

Rescuers pulled 14 victims from under the earth and debris that hit one neighborhood overnight Sunday, he said. Police, soldiers and villagers continued to search for an unknown number of people still missing.

Several other landslides cut off access to the town, Tenri Ajeng said, but those slides were not believed to have caused damage or fatalities.

Several days of flooding cut off villages and submerged more than 3,600 houses in the area, local media reported, forcing people to seek higher ground.

Landslides and flooding kill scores of people every year during the monsoon season in Indonesia, a tropical archipelago with a population of 235 million. Many people live and farm the fertile, but unstable mountain slopes

Landslides (Indonesia) #2

Case Study 1: Landslides in Indonesia kill 40


At least 40 people have been killed and scores more are missing in landslides on the Indonesian island of Flores, officials have said.

Dozens of homes were washed away in East Nusa Tenggara province and the road to the region's main town, Ruteng, has been cut off.

Rescuers are trying to dig out victims but are being hampered by bad weather.
Indonesia is in the middle of its rainy season, which each year sparks dozens of landslides.

Emergency supplies

Officials say at least 20 bodies have been pulled from mud after a hill collapsed in Cibal with scores still reported missing.

Local disaster management official, Yos Nono, said torrential rain had struck six hilly districts in the province.

Rescuers have been unable to move in heavy machinery because of the blocked roads.
"An evacuation team is digging to search for the victims, but we are facing problems because of bad weather and heavy rain," Mr Nono said.

The government is distributing emergency food supplies to those made homeless.

Landslides (Indonesia) #1

Overview

Landslide (or landslip) is a geological phenomenon which includes a wide range of ground movement, such as rock falls, deep failure of slopes and shallow debris flows, which can occur in offshore, coastal and onshore environments. Although the action of gravity is the primary driving force for a landslide to occur, there are other contributing factors affecting the original slope stability. Typically, pre-conditional factors build up specific sub-surface conditions that make the area/slope prone to failure, whereas the actual landslide often requires a trigger before being released.

Causes of a Landslide


The Mameyes Landslide, which, buried more than 100 homes, was caused by extensive accumulation of rains and, according to some sources, lightning.
Landslides are caused when the stability of a slope changes from a stable to an unstable condition. A change in the stability of a slope can be caused by a number of factors, acting together or alone. Natural causes of landslides include groundwater (porewater) pressure acting to destabilize the slope, loss or absence of vertical vegetative structure, soil nutrients, and soil structure, erosion of the toe of a slope by rivers or ocean waves, weakening of a slope through saturation by snowmelt, glaciers melting, or heavy rains, earthquakes adding loads to barely-stable slopes,earthquake-caused liquefaction destabilizing slopes.

Types of Landslides

Debris flow
Slope material that becomes saturated with water may develop into a debris flow or mud flow. The resulting slurry of rock and mud may pick up trees, houses and cars, thus blocking bridges and tributaries causing flooding along its path.
Debris flow is often mistaken for flash flood, but they are entirely different processes.

Muddy-debris flows in alpine areas cause severe damage to structures and infrastructure and often claim human lives. Muddy-debris flows can start as a result of slope-related factors and shallow landslides can dam stream beds, resulting in temporary water blockage. As the impoundments fail, a "domino effect" may be created, with a remarkable growth in the volume of the flowing mass, which takes up the debris in the stream channel. The solid-liquid mixture can reach densities of up to 2 tons/m³ and velocities of up to 14 m/s (Chiarle and Luino, 1998; Arattano, 2003). These processes normally cause the first severe road interruptions, due not only to deposits accumulated on the road (from several cubic metres to hundreds of cubic metres), but in some cases to the complete removal of bridges or roadways or railways crossing the stream channel.

Damage usually derives from a common underestimation of mud-debris flows: in the alpine valleys, for example, bridges are frequently destroyed by the impact force of the flow because their span is usually calculated only for a water discharge. For a small basin in the Italian Alps (area = 1.76 km²) affected by a debris flow, Chiarle and Luino estimated a peak discharge of 750 m3/s for a section located in the middle stretch of the main channel. At the same cross section, the maximum foreseeable water discharge (by HEC-1), was 19 m³/s, a value about 40 times lower than that calculated for the debris flow that occurred.

Earth flow
Earth flows are downslope, viscous flows of saturated, fine-grained materials, which move at any speed from slow to fast. Typically, they can move at speeds from 0.17 to 20 km/h. Though these are a lot like mudflows, overall they are slower moving and are covered with solid material carried along by flow from within. They are different from fluid flows in that they are more rapid. Clay, fine sand and silt, and fine-grained, pyroclastic material are all susceptible to earth flows. The velocity of the earth flow is all dependent on how much water content is in the flow itself: if there is more water content in the flow, the higher the velocity will be.
These flows usually begin when the pore pressures in a fine-grained mass increase until enough of the weight of the material is supported by pore water to significantly decrease the internal shearing strength of the material. This thereby creates a bulging lobe which advances with a slow, rolling motion. As these lobes spread out, drainage of the mass increases and the margins dry out, thereby lowering the overall velocity of the flow. This process causes the flow to thicken. The bulbous variety of earth flows are not that spectacular, but they are much more common than their rapid counterparts. They develop a sag at their heads and are usually derived from the slumping at the source.

Earth flows occur much more during periods of high precipitation, which saturates the ground and adds water to the slope content. Fissures develop during the movement of clay-like material creates the intrusion of water into the earth flows. Water then increases the pore-water pressure and reduces the shearing strength of the material.

Debris avalanche
A debris avalanche is a type of slide characterized by the chaotic movement of rocks soil and debris mixed with water or ice (or both). They are usually triggered by the saturation of thickly vegetated slopes which results in an incoherent mixture of broken timber, smaller vegetation and other debris. Debris avalanches differ from debris slides because their movement is much more rapid. This is usually a cause of lower cohesion or higher water content and commonly steeper slopes.

Movement
Debris slides generally begin with large blocks that slump at the head of the slide and then break apart as they move towards the toe. This process is much slower than that of a debris avalanche. In a debris avalanche this progressive failure is very rapid and the entire mass seems to somewhat liquefy as it moves down the slope. This is caused by the combination of the excessive saturation of the material, and very steep slopes. As the mass moves down the slope it generally follows stream channels leaving behind a V-shaped scar that spreads out downhill. This differs from the more U-shaped scar of a slump. Debris avalanches can also travel well past the foot of the slope due to their tremendous speed.

Sturzstrom
A sturzstrom is a rare, poorly understood type of landslide, typically with a long run-out. Often very large, these slides are unusually mobile, flowing very far over a low angle, flat, or even slightly uphill terrain.

Shallow landslide
Landslide in which the sliding surface is located within the soil mantle or weathered bedrock (typically to a depth from few decimetres to some metres). They usually include debris slides, debris flow, and failures of road cut-slopes. Landslides occurring as single large blocks of rock moving slowly down slope are sometimes called block glides.

Shallow landslides can often happen in areas that have slopes with high permeable soils on top of low permeable bottom soils. The low permeable, bottom soils trap the water in the shallower, high permeable soils creating high water pressure in the top soils. As the top soils are filled with water and become heavy, slopes can become very unstable and slide over the low permeable bottom soils. Say there is a slope with silt and sand as its top soil and bedrock as its bottom soil. During an intense rainstorm, the bedrock will keep the rain trapped in the top soils of silt and sand. As the topsoil becomes saturated and heavy, it can start to slide over the bedrock and become a shallow landslide. R. H. Campbell did a study on shallow landslides on Santa Cruz Island California. He notes that if permeability decreases with depth, a perched water table may develop in soils at intense precipitation. When pore water pressures are sufficient to reduce effective normal stress to a critical level, failure occurs.

Strategies

If you want to avoid being a landslide victim, the easiest thing to do is avoid building on steep slopes or close to edges of mountains. Don’t build near drainage ways or natural erosion valleys. Also beware of steep or hummocky slopes. If you are buying a home, look for the signs of weak earth below the structure - doors and windows that jam easily; cracks in the walls; unstable walls, walks, or stairs; leaking pools; fences or poles that are tilted at odd angles; and water seepage or bumps of earth at slope bottoms.

If you live in a landslide-threatened area, try not to water the slopes if possible. If there are large rocks on the slopes above your house, remove them so they can’t do damage in case they fall. It might also be helpful to plant vegetation on the slopes, so their roots will anchor the soil more firmly. Some people also cover their slopes with tarps in attempts to prevent the soil from slipping.

Droughts (Indonesia) #3

Case Study 2: Drought in Indonesia (2009)

Months before another El Ni*o, expected to deepen drought around the country, hundreds of rice paddies have already produced failed harvests.
Data from the Agriculture Ministry showed that 26,388 hectares of rice paddies suffered from drought in the April to June period due to water shortages.
"However, the figure is still far lower than it was in the 2003 to 2007 period when an average of 82,472 hectares of rice paddies suffered from drought each year," Ati Wasiati, director for the protection of food crops at the Agriculture Ministry told The Jakarta Post on Thursday.

She remained optimistic about the target to plant rice in 5 million hectares up until September despite the expected impacts of the El Ni*o phenomenon.
El Ni*o, a climate phenomenon with significant influence on global weather and ocean conditions, is predicted to hit the Asian region, including Indonesia, later this year or in early 2010.

The phenomenon, associated with warmer tropical waters in the Pacific, occurs once every two to five years and continues for about 12 months.
El Ni*o last occurred in 1997, 2002 and 2006, causing huge forest fires in Indonesia and resulted in decreased food production due to water shortages.
The country currently has about 12.4 million hectares of rice paddies, 4 million of which are irrigated.

In 1997, Indonesia exported about 5 million tons of rice due to prolonged drought caused by the effects of El Ni*o.

President Susilo Bambang Yudhoyono has warned of food shortages as a result of the return of El Ni*o and has asked the Meteorology, Climatology and Geophysics Agency (BMKG) to continue to closely monitor the development of climatic phenomenon.
Gatot Irianto, an climate change expert from the Agriculture Ministry dismissed the severe impacts of the El Ni*o on food shortage.

"Rains will occur when El Ni*o hits, which will create warmer temperatures at sea and cause evaporation," he said.

He added the country was likely to experience the peak of the drought until the end of August.

Kompas reported that droughts had hit several areas including 1,600 hectares of rice paddy fields in West Java,Yogyakarta and Aceh, with soil cracking from a lack of water.

Paskah Suzetta, a state minister and the head of the National Development Planning Board (Bappenas), previously said that El Ni*o would increase the state budget deficit.

"The government's precautionary efforts to counter the effects of El Ni*o may expand the state budget deficit from about 1.5 percent to 1.7 percent," he said.
Environmental activists have also warned that El Ni*o will cause severe forest fires across the country.

As of July 17, WWF Indonesia had detected about 9,841 hot spots in the country, mostly in Riau, with 4,581 hot spots and West Kalimantan with 1,010 hot spots.
The 1997 forest fires resulted in Indonesia being the world's third-largest emitter of greenhouse gas emissions. The smoke from those fires was blown as far away as Malaysia and Singapore.

Droughts (Indonesia) #2

Case Study 1: Drought in Indonesia (1997/98)


The 1997-98 El Niño had significant social and economic implications for Indonesia. A large part of the country suffered from severe drought, resulting in a huge shortfall in rice production that necessitated the import of over five million metric tons of rice to ensure food availability to the economically weaker sections of the society. In the forestry sector, the effects of large-scale forest fires during 1997-98 were unprecedented, damaging more than 9.7 million ha of forest area. The smoke and Trans boundary haze from these fires affected not only Indonesia but also other Southeast Asian countries, in particular Brunei Darussalam, Malaysia and Singapore. In addition to impacts on the agriculture and forestry sectors, the 1997-98 drought and fires also significantly affected other sectors such as transportation, tourism and public health.

Given that the linkage between El Niño events and drought in Indonesia has been well established scientifically, it is important to analyze why this scientific understanding did not translate into effective countermeasures essential to mitigate the worst effects of El Niño 1997-98. This report presents an analysis of the impacts of the 1997-98 El Niño event on Indonesia and identifies lessons learned that will be helpful in dealing with future extreme climate events.

Impacts on agriculture and food security:

Rice production in Indonesia is heavily influenced by the monsoon rain patterns, which have an important bearing on agricultural performance during the main (wet) and secondary (dry) seasons. The wet season normally extends from October to March and produces 60 percent of the country's annual rice crop and half of its maize, soybean and groundnuts. The dry season covers April to September, during which the remaining annual crops are produced.

The rainfall anomalies during the wet season 1997-98 caused a decrease in area under rice cultivation by 380,000 ha (3.4% below the previous wet season). Farmers planted maize as a compensatory crop in areas where paddy could not be planted. The switching over to maize was to the extent of 266,000 ha more than the area normally cropped with maize (an 8% increase from the previous wet season). The reduced rice production, coinciding with the economic crisis which began in 1997, led to a 300 percent increase in the price of rice. The government of Indonesia imported over 5 million metric tons of rice in order to maintain price levels and to ensure the availability of food to the economically weaker sections of the population.

Droughts (Indonesia) #1

Introduction

Though droughts are simply a significant deficit in moisture availability, they have been categorised into three different situations. Meteorological Drought is a situation where there is a significant decrease from normal rainfall over an area. Agricultural Drought occurs when soil moisture and rainfall is inadequate during the growing season to support crops and causes crop stress and wilting. Hydrological Drought is said to have occurred when lakes and reservoirs dry up and there is a fall in the groundwater level. Socioeconomic Drought occurs when the demand for an economic good exceeds supply as a result of a weather-related shortfall in water supply.



Indian Ocean Shift and Global Warming Seen Stoking Indonesia Droughts

Annual variations in Indonesia's climate are largely determined by the El Niño/Southern Oscillation (ENSO) system. However, extreme drought can also result from the cooling of sea surface temperatures near Sumatra caused by a similar ocean-atmosphere phenomenon--the Indian Ocean Dipole (IOD). These two systems have a past and present relationship to the Asian monsoon .Scientists findings reveal that drought frequency and duration in Indonesia can be expected to increase with global warming.

Future Implications:

Most scientists agree that as greenhouse gas (GHG) emissions increase and global temperature rises, the Asian monsoon, which has been decreasing in strength since the middle Holocene, is likely to intensify. A number of uncertainties prevail, however, including the impact of a changing ENSO and the influence of human-produced aerosols.

Still, if the relationships between these climate systems hold, more droughts in Indonesia and possibly throughout the Australasian region, could have substantial socio-economic impacts, such as an increased occurrence of forest fires.
All of these likely physical effects will present greater challenges to Indonesia, which has already lost large tracts of forest to deforestation and illegal logging practices and has a national poverty rate of around 27%. Achieving reductions in poverty and furthering sustainable development initiatives are therefore all the more critical.

More droughts could disrupt agriculture, slow an Indonesian drive to end poverty, lead to more wildfires that cause both smog and deforestation, threaten wildlife habitats and disrupt hydropower generation. The scientists said recent stronger monsoons had been widely linked by scientists to a global warming blamed on human burning of fossil fuels. But most studies of monsoon have focused on the likelihood of more rains in India and other parts of Asia.

"Our findings suggest that the some of the knock-on effects will cause more widespread consequences ... than previously thought," said Nerilie Abram of the Australian National University of the report in the journal Nature.

Volcanic Eruptions (Indonesia) #3

Case Study 2: 1816 -“Year Without a Summer”
After-Effects of the 1815 Eruption – Climatic Changes

1816 is the second coldest year in the northern hemisphere since CE 1400. The eruption also produced at least 1011 kg of SO4, leading to average global temperatures decreased about 0.4–0.7 °C (0.7–1.3 °F).

“In the spring and summer of 1816, a persistent dry fog was observed in the northeastern U.S. The fog reddened and dimmed the sunlight, such that sunspots were visible to the naked eye. Neither wind nor rainfall dispersed the "fog". It was identified as a stratospheric sulfate aerosol veil.”

“In summer 1816, countries in the Northern Hemisphere suffered extreme weather conditions.”

“On 4 June 1816, frosts were reported in Connecticut, and by the following day, most of New England was gripped by the cold front.”

“On 6 June 1816, snow fell in Albany, New York, and Dennysville, Maine. Such conditions occurred for at least three months and ruined most agricultural crops in North America.”

“Canada experienced extreme cold during that summer. Snow 12 inches deep accumulated near Quebec City from 6 to 10 June 1816.”

“In May 1816, frost killed off most of the crops that had been planted, and in June two large snowstorms in eastern Canada and New England resulted in many human deaths.”

“Rainfall was also unusually high across much of Europe during the summer of 1815.”

“Temperatures in western and central Europe were 1-2 º C cooler than the average for the period 1810-1819.”

Volcanic Eruptions (Indonesia) #2

Case Study 1: Tambora, 1815 Volcanic Eruption in Indonesia

Tambora is located on Sumbawa Island, on the eastern end of the Indonesian archipelago. The volcano, which began rumbling on April 5, lasted for 2 hours. Over the next three or four days, 50 km³ of magma was expelled in the form of ash fall and pumice-rich pyroclastic flowed. The eruption was the largest ever recorded and its effects were noted throughout the world. There had been no signs of volcanic activity there for thousands of years prior to the 1815 eruption. On April 10, the first of a series of eruptions that month sent ash 20 miles into the atmosphere, covering the island with ash to a height of 1.5 meters. The magnitude was seven on the Volcanic Explosivity Index (VEI)1 scale.

On the island of Sumbawa, it is estimated that 10,000 people were killed by pyroclastic flows, 32,000 by starvation and another 10,000 due to disease and hunger.
The 1815 Tambora eruption is the largest observed eruption in recorded history. The explosion was heard 2,600 kilometers away, and ash fell at least 1,300 kilometers away. Pitch darkness was observed as far away as 600 kilometers from the mountain summit for up to two days. The eruption expelled a total of approximately 140 gigatonnes of magma and generating an ash cloud that reached a height of up to 43 km. More than 95 percent of the ejected mass was erupted as pyroclastic flows that spread at least 20 kilometers from the summit, with 40 percent of this ending up as ash fallout. Floating pumice rafts and charred tree trunks hindered shipping in the area for three years after the eruption.

The Volcanic Explosivity Index (VEI) was devised by Chris Newhall of the U.S. Geological Survey and Steve Self at the University of Hawaii in 1982 to provide a relative measure of the explosiveness of volcanic eruptions