Fifteen people are known to have died and at least 45 more have been injured following a landslide at a jade mine near Hpakant in Kachin State, Myanmar, on Saturday 14 July 2018. The incident occurred on a spoil heap, where people were scavenging for any jade that may have been missed by the mine-operators, and it is feared that others may be unaccounted for in this incident as spoil-heap workers, known as Yay Ma Say, are often reluctant to discuss
their activities with outsiders, even rescue workers, due to the
legally dubious nature of the work.
Myanmar is the world's largest producer of jade, though much of this is produced (along with other precious and semi-precious minerals such as amber) at unregulated (and often illegal) artisanal mines in the north of the country, from where it is smuggled into neighbouring China. Accidents at such mines are extremely common, due to the more-or-less total absence of any safety precautions at the site. At many sites this is made worse by the unregulated use of explosives to break up rocks, often leading to the weakening of rock faces, which can then collapse without warning. The majority of people in this industry are migrant workers from the surrounding countryside, not registered with any local authority, which can make it difficult for rescuers to identify victims following such events, or even gain accurate assessments of the number of people likely to have been involved in such accidents.
The incident occurred following several hours of rain in the area associated with the Southeast Asian Southwest Monsoon, which has also caused a series of landslips and flash floods in the area. 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 Myanmar.
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.
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