Volcano:
A
volcano is a rupture in the crust of a planetary-mass object, such as Earth,
that allows hot lava, volcanic ash, and gases to escape from a magma chamber
below the surface.The volcano has got lot of parts and each one has another
function.
VOLCANO PARTS:
-Ash: Fragments of lava or rock smaller than 2mm in size that are blasted
into the air by volcanic explosions
-Lava flow: The far that the lava travels depends on the temperature of the
flow
- Lava dome:
Roughly circular month-shaped protrusion resulting from the slow extrusion of
viscous lava from a volcano.
-Lava: Molten rock that erupts from a volcano that solidifies as it cools
-Vent: Are the locations from which lava flows and pyroclastic material are
erupted.
-Tephra: Fragments of rock that are produced when magma or rock is
explosively ejected.
-Crater: Mouth of volcano – surround a volcanic vet
-Lahar: Is a type of mudflow or debris flow composed of a slurry of
pyroclastic material, rocky debris, and water.
-Fissure: Is a linear volcanic vent trough with lava erupts, usually
without any explosive activity.
-Dike: Magmatic dikes form when magma intrudes into a crack then
crystallizes as a sheet intrusion, either cutting across layers of rock or
through an unlayered mass of rock.
-Magma: Molten rock beneath Earth´s surface
-Magma chamber: A magma chamber is a large pool of liquid rock found
beneath the surface of the Earth
WHAT IS A PILLOW LAVA?
Pillow lavas are lavas that contain characteristic pillow-shaped structures
that are attributed to the extrusion of the lava under water. Pillow lavas in
volcanic rock are characterized by thick sequences of discontinuous pillow-shaped
masses, commonly up to one metre in diameter.
FORMATION:
They are created when magma reaches the surface but, as there is a large
difference in temperature between the lava and the water, the surface of the
emergent tongue cools very quickly, forming a skin. The skin cools much faster
than the inside of the pillow, so it is very fine-grained, with a glassy
texture. The magma inside the pillow cools slowly, so is slightly coarser
grained than the skin, but nevertheless it is still classified as fine grained.
As a whole, the Cantabrian
Mountains are remarkable for their intricate ramifications, but almost
everywhere, and especially in the east, it is possible to distinguish two
principal ranges, from which the lesser ridges and mountain masses radiate. One
range, or series of ranges, closely follows the outline of the coast; the
other, which is loftier, forms the northern limit of the great tableland
of Castile and León, and is sometimes regarded as a continuation of the Pyrenees.
In some parts the coastal range rises sheer above the sea, and everywhere has
so abrupt a declivity that the streams which flow seaward are all short and
swift.
