aci 1 Flashcards
The Philippines is in a zone within the Pacific Ocean that covers a collection of moving plate edges forming a “ring” of volcanoes that cause
earthquakes.
Pacific Ring of Fire or the Circum-Pacific Belt.
40 000-kilometer, horseshoe-shaped basin that is associated with
oceanic trenches, volcanic arcs, and plate movements.
Pacific Ring of Fire
Volcanic Activities
Emission of gases, flowing of lava outside the surface and sudden violent explosive bursts
also known as magma rises toward the surface, eventually forming a magma chamber.
Buoyant molten rock
Most active volcanoes in the Philippines are found in
volcanic arcs
chains of volcanoes formed by subducting plates.
volcanic arcs
There are two types of volcanic arcs
continental volcanic arc and island
volcanic arc.
are formed when an oceanic plate subducts
underneath a continental crust,
Continental volcanic arcs
when an oceanic plate subducts underneath another oceanic plate, this causes magma to rise and form a whole series of volcanic islands to pop out in the ocean.
island volcanic arc.
There are five distinct volcanic arcs in the Philippines where the volcanically active region
can be found, namely:
the Luzon Volcanic Arc, the East-Philippine Volcanic Arc, the Negros-Panay Arc, the Sulu-Zamboanga Arc, and the Cotabato Arc.
are those that erupted within the last 10 000 years. This can be indicated
by historical reports or radiometric dating.
Active volcanoes
As of 2008, the Philippine Institute of Volcanology and Seismology (PHIVOLCS) listed
23 active, 26 potentially active, and 281 inactive
volcanoes.
one of the three types
of volcanoes commonly characterized by a conical shape, a nearly symmetrical structure
with a steep summit, and more gradually sloping sides.
stratovolcano
is a volcanic landform associated with depression in a circular form and has a diameter exceeding one kilometer.
caldera
There are a total of – craters and four maars
on the Taal Volcano Island.
47
