Earthquake education using animations

Bangladesh is one of the most disaster-prone countries in the world. In addition to frequent cyclones and drought, large areas of the country are at risk of earthquakes.
With densely populated cities, even a relatively small earthquake could have catastrophic consequences. Amrai Pari (Together We Can Do It) is harnessing the power of animation to help people be better prepared. Find out more about the project: http://bbc.in/2gsG8Tx

Poverty and natural disasters

Over the last 20 years, 90% of all deaths due to natural disasters occurred in low and middle-income countries.

More information: https://www.weforum.org/agenda/2016/10/why-ending-poverty-is-key-to-reducing-deaths-from-disasters

disasters_poverty

In the path of a hurricane

Hurricanes are one of the planet’s most destructive natural weather phenomenons. With Hurricane Matthew currently making it’s way through the Caribbean, it’s important that communities adhere to local emergency services and action plans.

Hurricane Genesis

Hurricanes are very large storm whose birth originates in the tropical oceans. They rotate about a central axis commonly called ‘the eye’. The oceans are a massive source of heat energy. Variations in sea surface temperature result in pressure differences in the atmosphere which cause storms to build up.

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Tropical storms are characterised by their geographic origins. Image: NASA

To be classified as a hurricane a storm must reach wind speeds of at least 74 miles per hour. The rotation of the Earth gives these storm their characteristic spiral shape. Cyclonic storms in the northern hemisphere rotate anticlockwise while those in the southern hemisphere rotate clockwise.

Hazards

The main hazards from hurricanes are strong winds (up to 150 miles per hour for the very large storms) and high volumes of rain. Hurricane winds can uproot trees and destroy houses. Large amounts of rainfall in a short period of time can cause floods and rising groundwater tables.

The water-clogged landscape remains unstable, with increased risk of landslides and surface failures, for many years after a particularly large event. For example, there were increased number of landslides in Taiwan for 6 years after Cyclone Bhola.

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Extensive damage after the 2005 hurricane Katrina. Total damage > $100 billion USD. Image: Mark Wolfe

Historically significant hurricanes

The effect hurricanes have on people’s lives is illustrated by the word hurricane itself; after the Caribbean god of evil, Hurrican. They are a devastating force of nature.

  • Cyclone Bhola (1970) is historically the worst event for deaths with reported numbers as high as 500,000 people dead, mostly in Bangladesh.
  • Hurricane Katrina, which struck the east coast of the U.S. in 2005 is the most costliest hurricane with overall damage exceeding $100 billion.
  • The 1979 Cyclone Tip was the most intense hurricane ever recorded with wind speeds around 190 miles per hour. It was also the largest hurricane with a diameter around 2,170 kilometres.
  • Hurricane Sandy (U.S. east coast, 2010) was an abnormally large event due to the fusion of a tropical hurricane and a winter storm. With rising temperatures due to global warming these hybrid-storms are expected to become more frequent.

What can we do?

Cyclone Mahasen hit Sri Lanka, Bangladesh and Burma last season in May and resulted in far less deaths than expected thanks to swift action from the local governments. This shows that rapid response can save lives.

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Proper preparation and sufficient warning can save thousands of lives every year.

Houses with appropriate shelters (as in the U.S.) need to be built in hurricane prone regions. Proper training should be given from early school level onwards on the appropriate actions to take before and after such events: e.g. having enough clean drinking water, tinned food, spare batteries for lights, mobile phone chargers, first aid kits etc.

Have a rapid response system in place from the national governmental level to manage pre-event evacuation (if needed) and post disaster recovery.

There is no clear agreement on what sort of effects climate change and global warming will have on hurricanes. However most scientists agree that the change will be for the worse whether it is in the form of increased number of hurricanes each year, increased size of the hurricanes or changes to the length of the hurricane season .  We need to invest more into understanding the science behind these storms and the effects global warming will have on their magnitude and frequency of occurrence.

More information
[1] National Hurricane Centre
[2] George M. Dunnavan & John W. Dierks (1980). An Analysis of Super Typhoon Tip (October 1979), Joint Typhoon Warning Center,1980
[3] www.weather.com/maps/news/atlstorm18/gulfofmexicosatellite_large.html

Eruptions at Piton de la Fournaise volcano

Spectacular drone footage of the recent eruptions at Piton de la Fournaise volcano on Reunion Island.

Earth’s Average Temperature since the last ice age

A fantastic figure created by the wonderful Randall Munroe of xkcd.

 

Food insecurity follows floods in Sri Lanka

By Amantha Perera

Food shortages brought on by extreme weather events have resulted in almost a quarter of Sri Lanka’s 21 million people becoming malnourished, says a World Food Programme (WFP) document.

“The increased frequency of natural disasters such as drought and flash floods further compounds food and nutrition insecurity,” says the document, the latest WFP country brief for Sri Lanka, released in June.

As per WFP’s most recent Cost of Diet Analysis, almost 6.8 million (33 per cent) Sri Lankans cannot afford the minimum cost of a nutritious diet and a large portion of this vulnerable population lives in poverty and is frequently subjected to extreme weather events.

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Loss of land and livelihood from flooding caused to erratic monsoon rains. Image from Flickr.

In May heavy rains, brought on by Cyclone Roanu, affected 340,000 persons in 22 of the island’s 25 districts. “These people have very limited coping mechanisms, and these kinds of disasters can drive them deeper into poverty,” says minister for disaster management Anura Priyadarshana Yapa.

After the landslides and rains the government decided to shift out those living in high-risk areas but, according to public officials, they were faced with the problems of locating safe land and making income from agriculture.

“Most of those living on these high-risk areas rely on agriculture and we need to see how to secure their livelihoods,” head of the disaster management centre, Kegalle district, tells SciDev.Net.

The UN estimates that every year around 700,000 Sri Lankans are impacted by extreme weather, some repeatedly. “A sizeable segment of the flood affected population are squatters living in vulnerable areas prone to frequent flooding,” the UN Office for the Coordination of Humanitarian Affairs said following estimates made soon after the May floods and landslides.

“We need to develop long-term solutions, not stop-gap answers,” says Yapa, agreeing that there were serious problems arising from erratic weather patterns in Sri Lanka in recent years.

This article was originally published on SciDev.Net. Read the original article.

 

Earth’s Changing Surface water

Scientists have used satellite observations to study how the distribution of land and water on the Earth’s surface has changed over the last 30 years.

They found that the Earth’s surface has gained 115,000 sq km of water of extra water bodies and 173,000 sq km of water has now become land. The study is published in Nature Climate Change.

The interactive Aqua Monitor was developed by the Deltares Research Institute in the Netherlands. It is the first global-scale tool that shows, with a 30 metre resolution, where water has been transformed into land and vice-versa.

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New lakes – seen in blue – are appearing on the Tibetan Plateau. Image: Deltares Aqua Monitor

The largest increase in water has been on the Tibetan Plateau, where increased water from melting glaciers are creating huge new lakes.

A rise in the number of dams built over the last 30 years has also increased the number of inland water bodies. Using the satellite data, the team were able to identify previously unreported constructions in Myanmar and North Korea.

The Aral Sea, which lies between Kazakhstan and Uzbekistan, has seen the the greatest conversion of water into land. Formerly one of the four largest lakes in the world, the Aral Sea has been steadily shrinking since the 1960s after the rivers that fed it were diverted by Soviet irrigation projects.

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The Aral Sea has almost completely dried out. Green here shows the area of water that has converted to land. Image: Deltares Aqua Monitor

There have also been striking changes along our coastlines. The largest coastal water to land change is the construction of Palm Island and adjacent islands along the coast of Dubai. Many countries have shaped and extended their coastlines by land reclamation, including almost the entire coastline of eastern China from the Yellow Sea all the way down to Hong Kong.

Big data at everyone’s fingertips
Universally-available analytics for big satellite data may have major implications for monitoring capacity. At the very local scale, members of the general public can now make assessments without expert assistance if their houses are threatened by coastal erosion. At the regional scale, countries can monitor their water body changes and assess flooding impacts and strategy for disaster risk reduction.

Jaap Kwadijk, the Deltares scientific director: “This has never been done before. So it is difficult to imagine all the new applications that will be made using this tool. But the tool can be used by everybody and so I am sure multiple applications will emerge in the next few years”.

Original Paper: http://www.nature.com/nclimate/journal/v6/n9/full/nclimate3111.html

 

Snow algae speeds up Arctic melting: Tiny creatures with a big impact

by Dr Stefanie Lutz

The enthusiastic skiers or snow hikers among you may have already experienced the red snow phenomenon, which is caused by tiny microorganisms – the snow algae. Often termed ‘watermelon snow’ because of its colour and scent, I would not recommend eating it though. All the algae need to thrive is sunlight and liquid water. That’s why they form massive blooms in the warm months in spring and summer. But too much sun is not good for them either. They produce their own ‘sunscreen’ in the form of red pigments (the so called carotenoids), that gives them their red colouration.

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Red snow algae sampled colelcted from the Mittivakat glacier in Greenland. Image copyright: Liane G. Benning

Red snow looks very pretty, but why should we care about these tiny organisms? Well, even the smallest organisms can have a large impact. The red coloration darkens snow and glacial surfaces. This decreases their so called albedo. The albedo determines how much sunlight is reflected back from a surface. White snow reflects more sunlight, whereas the darker red snow reflects less. Therefore more heat is retained, which causes more melting. It is the same effect that makes people choose white clothing in places with high sun exposure such as deserts. Black clothing would make the sun even more unbearable.

I was really lucky to work on this topic during my PhD at the University of Leeds. Together with my supervisor Liane G. Benning, we collected 40 samples from various places in the Arctic, ranging from Greenland to Iceland, Svalbard and Northern Sweden. We found that these algal communities are very similar in all studied places and over one melt season they reduce the albedo by an additional 13%. Calculating how much this equates in additional melting is not easy and will be addressed in our ongoing work.

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A colony of red snow algae under the microscope. Image copyright: Stefanie Lutz

Our findings have been published in Nature Communications. Since the paper was published I have been approached by a many worried journalists who aske me what we should do against these dreadful algae. Well, we cannot and should not do anything against them. Snow algae are actually very important members of the natural food chain. Like plants, they do photosynthesis, and in doing so they fix atmospheric CO2 and transform it into organic carbon that can be used by other organisms. However, there is one thing that is worrying – and that is global warming, which may cause a ‘runaway effect’. Snow algae need liquid water to bloom, with rising temperatures more melting will increase the extent of the snow algae, which will further darken the glacial surfaces, causing more melting, and so on. So the only thing we can and should do is to reduce human-induced climate change.

We’ve just come back from gathering samples from the Greenland Ice Sheet, where a record-breaking ice melting enderway. As part of a big international, UK led team, we will further investigate the extent of these algae and their contribution to melting. At the moment climate models don’t consider the effect of algae on snow and ice melt, it is time to change that!


Dr Stefanie Lutz is a postdoctoral research associate at the GFZ Helholtz centre in Potsdam, Germany.

When continents collide

Since 1900, 35 earthquakes worldwide have each killed at least 10,000 people. Of these, 26 were in the Alpine-Himalayan seismic belt – a broad “crumple zone” where the African, Arabian and Indian tectonic plates collide with Europe and Asia. Most of these deadly earthquakes were caused by the rupture of faults that had not previously been identified.

Tim Wright is Professor of Satellite Geodesy at the University of Leeds and Director of the Centre for the Observation and Modelling of Earthquakes, Volcanoes and Tectonics (COMET). His work has been at the forefront of developing the use of satellite radar for measuring tectonic and volcanic deformation.

Below is a lecture presented by Tim at the Geological Society talking about his work trying to understand the nature of seismic hazard within the Alpine-Himalayan region.

Quote: Marcia McNutt

“A natural hazard need not become a human disaster if society learns and applies lessons in preparation and resilience.”

Marcia McNutt, National Academy of Science, Engineering and Medicine.

Blogging about the natural and climate hazards on the 'pale blue dot' that is planet Earth

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