Saturday, September 18, 2021

Disasters that could end the world!

   Retrospective and alert to the present and future of our beautiful home!!!

 Tsunami.  Earthquake.  Nuclear crisis.  It came all at once to the Japanese.  A tremor of 9.0 on the Richter scale shook Japan on March 11, and the country had already counted almost 9,000 dead as of this edition's closing.  Another 13,000 people were still missing.

 The catastrophe drew worldwide attention not only for the lost lives and dramatic rescue efforts.  Japan is one of the countries best prepared to face natural disasters, and yet it was devastated by the force of nature.  A sign that no country is safe.

 In 2010, natural disasters killed at least 234,000 people and affected nearly 200 million others around the world.  No expert is able to say whether this number will decrease or increase going forward, but it is already known that the intensity of the catastrophes will increase.  Global warming will make the temperature rise – it will be as much as 3.5°C higher by 2035, according to the International Energy Agency.  That means more droughts, floods, eruptions, destructive hurricanes and even earthquakes.  And yes, there may be a link between these phenomena and human action.  On the following pages, you will discover the risks we take.  And how can we prepare.

 TSUNAMI

 Even with all precautions, Japan was no match for the ravaging wave.

 “A misfortune never comes alone,” the saying goes.  And geology proves it: after a great earthquake, there is always a tsunami – an expression in Japanese that retired “tidal wave” and means “wave that advances over the coast”.  Fortunately, it is necessary to reach at least 7 points on the Richter scale to set off this tide of destruction – this explains that there are only 8 serious occurrences in the last 10 years.  Of these, two were in Japan, the most recent in early March, caused by one of the biggest earthquakes in history.

 Nations overlooking the Pacific, such as the Japanese archipelago, are precisely those most at risk, due to the concentration of active volcanoes and areas in danger of earthquakes.  But tsunamis are not content with promoting marine trawls just close to where they form.  They can reach locations thousands of kilometers from their point of origin.  In 1960, there was one that started in Chile and crossed the ocean, passing through Hawaii and killing 200 people in Japan.

 Not even Brazil escapes.  The greatest known risk is that of earthquakes that can occur in the South Sandwich Islands (which link South America to Antarctica).  “They would generate tsunamis that could affect the Brazilian coast,” says Costas Synolakis, a geologist at the University of South California.  However, the real probability of this happening is not known for sure, as research is lacking.

 There are those who argue that, with global warming, the problem tends to increase.  London University expert Bill McGuide believes that melting at the poles should cause the earth's crust to move upwards, which will cause earthquakes and, consequently, tsunamis.  To make matters worse, prevention methods are still lame.

 In Japan, breakwaters built to contain the tidal waves didn't even start.  And most of the houses were not ready to withstand the force of the waters.  “Investments are lacking,” says Professor Synolakis.  For him, little has been done since the Indonesia disaster in 2004, which left 230,000 victims.  The main problems are the lack of mapping of which areas can be affected and the limited number of tsunamographs – as their name suggests, they are the devices that measure the frequency and size of waves.

 But the biggest stumbling block is the lack of information, as in the Samoa disaster in 2009, which left 189 victims.  Many tried to flee by car and, with the traffic, drowned in them.  The right thing would have been to walk to the high ground nearby and wait for the downpour to pass.

 To alleviate the tragedies, the warning needs to be quick and effective.  In Indonesia, in 2004, many of the 230,000 dead did not get to see the warning issued by local television.  The reason: they lived in villages without electricity.  But in many cases there is not even time to release the information: a tsunami formed near the coast can reach it in less than 10 minutes.  In Japan's recent case, the communication problem was aggravated because the earthquake had been so strong that it cut even the internet.

 Another necessary measure is to invest in an anti-tsunami architecture.  A good example is the Islamic temples in Indonesia, which passed unharmed by the avalanche of waves.  Its large circular columns, which supported the upper floors, allowed the water to flow freely.  Moral of the story: if you can't beat it, adapt to it.

 Probability of occurring - Average

 Lethality - Average

 Outlook for the future – Just like today

 Every year there are 6 tsunamis in the world

 DRILLING

 Japan's disaster will be the most expensive in history, analysts who calculate catastrophic losses have said.  The leader about to be ousted is a hurricane: Katrina.  In 2005, when it swept off the US coast, Katrina caused more than $100 billion in damage.  Where he came from, more powerful ones will come.  Hurricanes (name used in the Atlantic) and typhoons (name used mainly in the Pacific) are getting stronger.  Between 1981 and 2006, their speed increased by 7.8 meters per second, according to Florida State University, which analyzed the fastest.  The fury is driven by the surface of the oceans, which are getting hotter.  (Temperatures above 26°C are conducive to the formation of hurricanes.) The biggest targets could be the coasts of the US, Mexico and countries in the Caribbean Sea.  At first, Brazil is not at risk: our surroundings have strong winds, and hurricanes only form in calm areas.  But the weather can change.  In 2004, Catarina hit the state of Santa Catarina and killed at least 3 people.  “If we had one, it is possible that there will be another”, says Augusto José Pereira Filho, professor of atmospheric sciences at USP.

 Probability of occurring - High

 Lethality - High

 Outlook for the future – Getting worse

 VOLCANO

 Over the past 100 years, volcanoes have left 100,000 dead.  Considering the period, it's not much (car accidents, for example, kill 35,000 people a year in Brazil alone).  The main threat generated by the eruptions is the release of ash into the atmosphere, which would cause toxic rain and global cooling.  There are 6 supervolcanoes on the planet: three in the US, one in Japan, one in New Zealand and one in Indonesia.  Each could release an ash cloud 3,000 times larger than the one that covered Europe after the Icelandic Eyjafjallajökull erupted in 2010. Another danger lies in the Canary Islands, near northwest Africa.  There is a volcano there whose eruption would cause large blocks of stone to break off the islands, generating a tsunami that would flood the south of the United Kingdom, devastate the American east coast and reach the Brazilian Northeast with waves up to 3 meters high.

 Probability of occurring - Average

 Lethality - Low

 Outlook for the future – Just like today

 EARTHQUAKE

 It is not a strictly natural phenomenon – it can also be caused by man.  But science has a new weapon for studying it.

 Science cannot predict earthquakes.  But experts believe that with big cities like Tokyo and Los Angeles built in unstable regions, the tendency is to have at least one big tragedy per decade.  400 million people live in metropolises that could suffer a major earthquake in the next 200 years.  “No city is prepared for a tremor of 9 degrees on the Richter scale, like what happened in Japan”, explains professor of seismology Afonso Vasconcelos Lopes, from USP.  That's because the buildings are designed to withstand the worst earthquake ever at the site – and few places have ever suffered 9-degree earthquakes.

 Unlike Japan, Brazil is in a geologically stable area.  But that's not an absolute guarantee.  “Even in a city like São Paulo, which in theory is safe, it is necessary to calculate the resistance of the works”, says Vasconcelos.  Is that there is a type of earthquake, called intraplaque, which can happen even in supposedly immune regions.  This phenomenon is caused by weaknesses in the tectonic plates and is responsible for 10% of earthquakes on the planet.  The US suffered an 8-degree intraplate earthquake at the beginning of the 19th century, and there was one in Brazil as well – a 6.2-degree tremor in the Tombador mountain range, in Mato Grosso, in 1955.

 Furthermore, earthquakes are no longer strictly natural disasters.  The one in Sichuan, which killed 69,000 people in China in 2008, may have been triggered by the construction of a dam.  Columbia University scientists believe the weight of the water would have affected the site's seismic balance.  The Chinese government did not release the records of the event, preventing the thesis from being studied in depth.  But it is accepted by most experts.  Even because it wasn't the first time this happened.  When the Hoover Dam was built in the US in the 1930s, the region where it is located (near Las Vegas) suffered hundreds of 4 to 5 degree shocks.

 But seismologists have a new weapon.  It's Quake Catcher, a software that was created by Stanford University.  This program uses sensors present on any computer's hard drive to measure the seismic activity of the location where it is located and sends the information to scientists.  If millions of people install the program, researchers will have a more detailed picture of seismic activity on Earth – for one day, who knows, they will be able to predict earthquakes.

 Probability of occurring - High

 Lethality - High

 Outlook for the future – Getting worse

 FLOODS

 It's not your impression: it's getting worse.  The last decade concentrated 50 of the 180 biggest floods of the last 100 years.  Despite having less brand than other disasters, floods kill a lot.  Last summer, the rains caused unprecedented damage in Rio de Janeiro: 700 dead and 14,000 homeless and homeless.  But nothing like China and India, where population density leads to tragedies with millions of victims – in addition to destruction, floods spread infectious diseases.

 The statistics that signal the increase of the problem have always been viewed with reservation by meteorologists.  For them, it takes a long historical sequence to prove a change.  Because this change began to be proven.

 For the first time, it has been proven that greenhouse gases cause increased rainfall.  In other words, it's not only getting worse, it's our fault.  “Now we can confidently say: the increase in rainfall intensity at the end of the 20th century cannot be explained by existing climate models,” researcher Gabriele Hegerl, research leader at the University of Edinburgh, UK, told Nature magazine.  It is only a first step, but it can still result in the compensation of rich countries for floods in poor regions in the future.  At least now science admits that the weather is bad.

 Probability of occurring - Very high

 Lethality - Very high

 Outlook for the future – Getting worse

 DRY

 The lack of water could reach two thirds of the world population in 2025. Large regions of Asia and Africa, as well as smaller parts of Australia, USA, Central America and South America (including the Brazilian northeast) are already in a situation of scarcity or getting closer to that.

 Continues after advertising

 The results can be devastating.  If it affects agriculture, drought is capable of forcing populations to migrate so as not to suffer from lack of food and disease.  In 1932, victims of drought in Ceará left the interior in search of help on the coast, for example.  Staying where they lived could lead to death – which happened to 1 million Ethiopians after a fall in rainfall in 1984. And the forecast is for the droughts to intensify.  The rise in global temperature has fueled soil evaporation in countries like Australia.  The rain generated by this steam has fallen in other regions, and the result is more arid soils.  To make matters worse, we are increasingly living in cities, where the water is polluted.  “We need to be more efficient with our resources,” says Michael Hayes, director of the US National Drought Mitigation Center.

 Probability of occurring - Average

 Lethality - Average

 Outlook for the future – Getting worse

 NUCLEAR CATASTROPHE

 Nuclear power plants are safe.  And they are getting safer still.  But something can always go wrong.  See which is the worst possible scenario.

 Since the first nuclear reactor started producing electricity in 1951, there has been only one serious accident – ​​at Chernobyl.  By the worst estimates, it caused 4,000 deaths.  Is enough.  But that's far fewer than the 300,000 people who die each year from pollution generated by burning fossil fuels.  Statistically, nuclear power plants are the safest way to produce energy.  And they are getting more secure.  In 1990, reactors around the world had an average of 1.8 scrum (unscheduled shutdown, usually triggered by the reactor's emergency systems) for every 7,000 hours of operation.  Today, this rate is 0.5.  In other words: the plants are working much better than in the past.

 Okay. Now tell this to the Japanese, who are seeing their country facing a nuclear crisis.  The risk of an accident is never zero.  The worst that could happen to the world would be a serious incident at the Kursk, Smolensk and Leningrad plants in Russia.  Altogether, they have 11 reactors of the RBMK-1000 type – the same one that was used in Chernobyl.  The problem is in the so-called containment, a steel and concrete structure that surrounds the nuclear reactor – and that the RBMK (an acronym in Russian for high-powered reactor) simply do not have.  “It is an ordinary, open building,” explains Fernando Carvalho, a professor of nuclear engineering at UFRJ.  This means that if the reactor explodes, it can release large amounts of material into the atmosphere.  That's what happened in Chernobyl, where a radioactive cloud formed that traveled 2,000 km and reached France.  In other nuclear plants, which have reactor containment structures, it would be difficult to have such a large leak.

 The most delicate point of any nuclear reactor, be it the RBMK type or the BWR (boiling water reactor, used in Japan) and PWR (pressurized water reactor, in the case of Angra 1 and 2) standards, is the refrigeration system.  The reactor needs to receive running water, which is pumped by an electrical system.  It cannot be left unrefrigerated under any circumstances.  Therefore, the mills take extreme precautions.  If there is a shortage of electricity, a backup system comes into play.  “The Angra plants have 4 diesel generators each.  That's four times more than would be necessary,” says Laércio Vinhas, director of security at the National Nuclear Energy Commission.  In Japan, these diesel generators were damaged by the tsunami – and the reactors were left without adequate cooling.  Nuclear fuel (in the case of Japanese power plants, uranium pellets) continues to release heat, even if the reactor is shut down.  If there is no refrigeration, the temperature rises dangerously – in half an hour, it goes from the normal level (285º C) to more than 800 degrees.  When the heat reaches 1200°C, the pads' coating melts.  This releases hydrogen – a highly flammable gas responsible for the explosions in Fukushima.  If nothing is done, the temperature continues to rise, there is a release of radioactive gases and, at 1800º C, the metal cylinder that protects the reactor begins to unravel.  After three days, the heat can reach 2400º C – when the uranium itself starts to melt.

 But why did Japan build a nuclear plant close to the coast in a region vulnerable to tsunamis?  Because of the water.  Many of the 442 existing reactors on the planet are located near the sea or rivers – precisely so that they have an abundant supply of water.

 The most modern reactors have passive cooling systems, that is, they work even if there is a total failure of the electric pumps and diesel generators.  Four such models are being built in China, scheduled to open in 2013. But even they are not without criticism – the US government says the new model, created by the American company Westinghouse, does not offer protection against terrorist attacks (because its structure would not withstand a plane crash).  But terrorists are unlikely to be able to hurl a plane into a nuclear power plant.  They are more likely to attempt a radiological attack.  A survey of 85 nuclear weapons experts estimated the probability of an attack of this type in a US city at 39.8% by 2015. First, terrorists seize some type of radioactive material – such as the cesium-137 used in machines of radiography.  It is attached to an ordinary bomb, which is detonated in the center of a metropolis.  This explosion causes a shower of radioactive particles that can spread over an area of ​​up to 40 blocks – which, depending on the degree of contamination, could become uninhabitable for months, years or even decades.

 The worst nuclear nightmare would be an armed conflict.  Simulations carried out by two American universities indicate that a nuclear conflict between India and Pakistan would leave 12 million dead.  Fires resulting from the explosions would release 5 million tons of soot into the atmosphere.  This would block some of the sunlight, cooling the planet by 1.25º C and reducing rainfall by 9%.  “The plantations would grow more slowly, and the harvests would be cut short.  And the biggest problem would be the panic [of contamination].  Countries would stop exporting and importing food,” says Alan Robock, a climatologist at Rutgers University and author of several studies on the subject.  The explosions would also have a catastrophic effect on the ozone layer, which would be reduced by up to 70% over a 5-year period.  But for this scenario to happen, India and Pakistan would need to detonate 50 atomic bombs each – a very difficult scenario to happen.

 Probability of occurring - Very low

 Lethality - Low

 Outlook for the future – Improve

 442 is the number of nuclear reactors operating on the planet.  The US is the country with the most reactors (104).

 11 is the number of RBMK-1000 reactors in use in Russia.  It is a model considered unsafe – the same as in the Chernobyl accident.

 SOLAR STORM

 One day, the Earth will be swallowed by the Sun – but only 7.6 billion years from now.  Until then, the worst that can happen is solar storms.  They are discharges of electromagnetic radiation that, upon reaching Earth, damage everything electrical or electronic – such as cars, planes, computers, satellites and energy transmission networks.  The worst case on record happened in 1859, when a storm burned much of the US telegraph lines.  Today, with our technological dependency, the consequences would be much worse.

 A US government report estimates that a major storm would cause $1 to $2 trillion in damage, from which it would take humanity 10 years to recover.  The main line of defense is prevention, with the shutdown of appliances and electrical networks before the storm.  The alarm would be given by Advanced Composititon

 Explorer, a NASA spacecraft that is 1.5 million km from Earth and is able to detect solar storms approximately one day before they arrive here.

 Probability of occurring - Low

 Lethality - Very low

 Outlook for the future – Getting worse

 ASTEROID

 Chance of collision is minimal.  But if it's big and on target, we're not ready yet.

 It's not a question of if but when.  An asteroid like the one that extinguished the dinosaurs, between 15 and 20 kilometers wide, is a very rare event: it hits the Earth every 100 million years, on average.  But stones between 50 and 100 meters, with the power to destroy a metropolis, fall more frequently: every 500 years.  Again, this is a historical average – that is, two may have fallen in the same week and none in the next 2000 years.

 The last of these unwanted visits was on June 30, 1908. It was the classic case of “if a tree falls in the middle of the Amazon, no one knows about it”, with the difference that it was an asteroid in the forest of Tunguska, Siberia, extreme northeast of the then Russian Empire.  Despite producing a shock wave that devastated an area equivalent to Greater São Paulo, there were 3 thousand square kilometers uninhabited.  No person died and the case had no repercussions.

 The next one – which no one guarantees will wait until 2408 – will find a more populated world, with 20 metropolitan regions of more than 10 million inhabitants.  Any one of them would be wiped out if hit by a space rock the size of a gymnasium.  The question is: what are we going to do when he comes?

 “In the future, we're going to predict a collision decades in advance and, when the time comes, avoid it,” says David Morrison, head of NASA's asteroid-watching division, which constantly reviews statistics.  "But for now, we're not safe."

 The last asteroid to prove this was the 2008 TC3, in October 2010. The size of an automobile, it was detected just 20 hours before impact, when it was 500,000 kilometers away – almost reaching the Moon. Luckily, it exploded at 37 km from the ground, over the desert on the border of Egypt with Sudan.

 For now, the plans are on paper – and look more like a blockbuster script.  Sending the most powerful bomb towards the asteroid, for example, is not as easy as it seems.  To deviate from its trajectory, it would be necessary to intercept it years in advance.  Another idea is to send a spaceship just to hover beside the asteroid and, with the gravitational force generated by its mass, change the boulder's original route.  A spacecraft with mirrors could direct sunlight to burn the asteroid: evaporation would try to deflect it away from Earth.

 According to NASA's accounts, two objects deserve attention: the 2007 VK184 and the 2011 AG5, which will be in terrestrial surroundings between 2036 and 2057. On the collision danger scale, they have a grade 1 out of 10 – “in the review of the calculations, they should come back to 0,” says Morrison.  All are possibilities.  Only one thing is certain: one day the stone will fall.

 Probability of occurring - Very low

 Lethality - Very high

 Outlook for the future – Just like today

 WILL…

 …falls to the ground

 The impact of a 50 meter diameter celestial body with the planet is equivalent to that of a nuclear bomb.  The larger the size of the object, the worse the damage.

 …sinks in the sea

 An asteroid falling into the ocean would also be deadly.  A 100 meter pile of rocks, for example, would cause a tsunami that would engulf coastal buildings

No comments:

Post a Comment