Two people have been injured after a landslide broke through a perimeter wall and swept away several lightly constructed houses in the Barangay Mercedes area of Catbalogan City, on Samar Island in the Philippines, on Tuesday 17 September 2019. The area had been identified as being at a high risk following heavy rains associated with Typhoon Marilyn, which swept past the islands last week, and an evacuation of the properties had been ordered by the authorities, but some people had remained, and it is unclear if they had been offered alternative accommodation. 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. The injured persons have been identified as Annabelle Cabarles, 36, and Kevin Cabarles, 14.
A landslide in the Barangay Mercedes area of Catbalogan City, which injured two people on 17 September 2019. Philstar.
Tropical storms are caused by the warming effect of the Sun over
tropical seas. As the air warms it expands, causing a drop in air
pressure, and rises, causing air from outside the area to rush in to
replace it. If this happens over a sufficiently wide area then the
inrushing winds will be affected by centrifugal forces caused by the
Earth's rotation (the Coriolis effect). This means that winds will be
deflected clockwise in the northern hemisphere and anti-clockwise in the
southern hemisphere, eventually creating a large, rotating Tropical
Storm. They have different names in different parts of the world, with
those in the northwest Pacific being referred to as typhoons.
Despite the obvious danger of winds of this speed, which can physically
blow people, and other large objects, away as well as damaging buildings
and uprooting trees, the real danger from these storms comes from the
flooding they bring. Each drop millibar drop in air-pressure leads to an
approximate 1 cm rise in sea level, with big tropical storms capable of
causing a storm surge of several meters. This is always accompanied by
heavy rainfall, since warm air over the ocean leads to evaporation of
sea water, which is then carried with the storm. These combined often
lead to catastrophic flooding in areas hit by tropical storms.
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