Monday, 18 June 2018

Flooding kills 23 in northeastern India.

Twenty three people have died in flooding in northeastern India since the Southwest Monsoon arrived in the area five days ago. Twelve of the deaths occurred in the state of Assam, where five people died on Sunday 17 June alone, with the remaining deaths occurring in Manipur, and severe flooding also reported in Tripura, and Mizoram. Thousands of people across the region have been forced to abandon homes and farms in the region, and it in addition to the Human casualties, large numbers of livestock have died.

Floodwaters in Assam this week. Anuwar Hazarika/Reuters.

Monsoons are tropical sea breezes triggered by heating of the land during the warmer part of the year (summer). Both the land and sea are warmed by the Sun, but the land has a lower ability to absorb heat, radiating it back so that the air above landmasses becomes significantly warmer than that over the sea, causing the air above the land to rise and drawing in water from over the sea; since this has also been warmed it carries a high evaporated water content, and brings with it heavy rainfall. In the tropical dry season the situation is reversed, as the air over the land cools more rapidly with the seasons, leading to warmer air over the sea, and thus breezes moving from the shore to the sea (where air is rising more rapidly) and a drying of the climate.

 Diagrammatic representation of wind and rainfall patterns in a tropical monsoon climate. Geosciences/University of Arizona.

Much of Southeast Asia has two distinct Monsoon Seasons, with a Northeast Monsoon driven by winds from  the South China Sea that lasts from November to February and a Southwest Monsoon driven by winds from the southern Indian Ocean from March to October. Such a double Monsoon Season is common close to the equator, where the Sun is highest overhead around the equinoxes and lowest on the horizons around the solstices, making the solstices the coolest part of the year and the equinoxes the hottest. However northeast India is largely protected from the Northeast Monsoon by the mountains to its north and east, though these can also add to the severity of flooding in the region, with melting snow in the Himalayas swelling the rivers that flow through these states,

The winds that drive the Northeast and Southwest Monsoons in Southeast Asia. Mynewshub.

See also...

http://sciencythoughts.blogspot.com/2018/05/landslip-at-mizoram-quarry-kills-four.htmlhttp://sciencythoughts.blogspot.com/2017/07/flooding-kills-at-least-seventy-three.html
http://sciencythoughts.blogspot.com/2016/07/woman-killed-by-landslide-in-guwahati.htmlhttp://sciencythoughts.blogspot.com/2016/01/magnitude-67-earthquake-in-manipur.html
http://sciencythoughts.blogspot.com/2014/06/at-least-seven-dead-following-heavy.htmlhttp://sciencythoughts.blogspot.com/2014/05/seven-members-of-one-family-killed-by.html
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Fireball meteor over Belgium.

Witnesses across northwestern Europe reported seeing a bright fireball meteor (a shooting star brighter than Venus) on Sunday 16 June 2018, according to the International Meteor Organization. The majority of the sightings occurred over Belgium, but the object was also seen from France, Germany, the Netherlands, England, Luxembourg and Switzerland, moving from southeast to northwest, and ending its journey somewhere in the area around the city of Li├Ęge.

 The 16 June 2018 fireball meteor observed from Durlach in Germany. Gernot Meiser/TWAN.

Fireball meteors are  typically caused by pieces of rock burning up in the atmosphere, but can be the result of man-made space-junk burning up on re-entry. Objects of this size probably enter the Earth's atmosphere several times a year, though unless they do so over populated areas they are unlikely to be noticed. They are officially described as fireballs if they produce a light brighter than the planet Venus. The brightness of a meteor is caused by friction with the Earth's atmosphere, which is typically far greater than that caused by simple falling, due to the initial trajectory of the object. Such objects typically eventually explode in an airburst called by the friction, causing them to vanish as an luminous object. However this is not the end of the story as such explosions result in the production of a number of smaller objects, which fall to the ground under the influence of gravity (which does not cause the luminescence associated with friction-induced heating).

 Map showing areas where sightings of the meteor were reported, and the route of the object (blue arrow). American Meteor Society.

These 'dark objects' do not continue along the path of the original bolide, but neither do they fall directly to the ground, but rather follow a course determined by the atmospheric currents (winds) through which the objects pass. Scientists are able to calculate potential trajectories for hypothetical dark objects derived from meteors using data from weather monitoring services.
 
See also...
 
http://sciencythoughts.blogspot.com/2018/06/meteorites-found-in-yunnan-province.htmlhttp://sciencythoughts.blogspot.com/2018/06/asteroid-2018-la-impacts-earth.html
http://sciencythoughts.blogspot.com/2018/04/the-lyrid-meteor-shower.htmlhttp://sciencythoughts.blogspot.co.uk/2018/03/fireball-over-olympic-penninsula.html
http://sciencythoughts.blogspot.co.uk/2018/01/fireball-meteor-over-michigan-causes.htmlhttp://sciencythoughts.blogspot.co.uk/2018/01/the-quadrantid-meteor-shower.html
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Landslide kills five in Mandalay Region of Burma.

Five people, described as all being members of the same family, have died in a landslide in the city of Mogok in the Mandalay Region of Myanmar. The incident happened at about 4.00 am local time on Thursday 14 June 2018, when the landslide hit a house in which the family were sleeping. The incident happened following several days of heavy rain in the area, associated with the southwest monsoon, which brings heavy rains to Myanmar between May and October. Landslides are a common problem after severe weather events, as excess pore water pressure can overcome cohesion in soil and sediments, allowing them to flow like liquids. Approximately 90% of all landslides are caused by heavy rainfall.This year's monsoon has been particularly severe, with floods and landslips occurring across the country, though so far these are the only reported fatalities.

The scene of the 14 June 2018 Mogok landslide. Hein Zaw Thu/Facebook/Radio Free Asia.

Monsoons are tropical sea breezes triggered by heating of the land during the warmer part of the year (summer). Both the land and sea are warmed by the Sun, but the land has a lower ability to absorb heat, radiating it back so that the air above landmasses becomes significantly warmer than that over the sea, causing the air above the land to rise and drawing in water from over the sea; since this has also been warmed it carries a high evaporated water content, and brings with it heavy rainfall. In the tropical dry season the situation is reversed, as the air over the land cools more rapidly with the seasons, leading to warmer air over the sea, and thus breezes moving from the shore to the sea (where air is rising more rapidly) and a drying of the climate.

 Diagrammatic representation of wind and rainfall patterns in a tropical monsoon climate. Geosciences/University of Arizona.

Much of Southeast Asia has two distinct Monsoon Seasons, with a Northeast Monsoon driven by winds from  the South China Sea that lasts from November to February and a Southwest Monsoon driven by winds from the southern Indian Ocean from March to October. Such a double Monsoon Season is common close to the equator, where the Sun is highest overhead around the equinoxes and lowest on the horizons around the solstices, making the solstices the coolest part of the year and the equinoxes the hottest. However Myanmar is largely protected from the Northeast Monsoon by the mountains separating the country from Yunnan Province in China.

 The winds that drive the Northeast and Southwest Monsoons in Southeast Asia. Mynewshub.

See also...

http://sciencythoughts.blogspot.com/2018/01/series-of-landslides-kill-at-least.htmlhttp://sciencythoughts.blogspot.com/2017/03/magnitude-51-earthquake-in-bago-region.html
http://sciencythoughts.blogspot.com/2017/02/nine-killed-in-landslide-at-myanmar.htmlhttp://sciencythoughts.blogspot.com/2016/12/lanslide-at-myanmar-jade-mine-may-have.html
http://sciencythoughts.blogspot.com/2016/11/myanmar-jade-mine-struck-by-possible.htmlhttp://sciencythoughts.blogspot.com/2016/08/magnitude-68-earthquake-in-magway.html
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