Volcano

• Cone is the most striking part of the volcano. It is usually composed of mixtures of lava and pyroclastic.
• Vent is the opening through which an eruption takes place. This main part of a volcano supplies the magma from the underlying source to the top of the volcano.
• Magme chamber is the large underground pool of liquid rock found beneath the Earth's crust.
• Crater is a basin-like depression over a vent at the summit of the cone.
• Caldera is a volcanic depression much larger than the original crater.
• Lava is the rock or magma expelled from a volcano during eruption.
• Dikes are the barrier or obstacles in a volcano.
• Sills otherwise known as intrusive sheets, are solidified lava flows that originally forced their way between and parallel to older layers of rocks.
• Conduit is a channel or pipe conveying liquid materials such as magma.
• Flanks is the side of a volcano.
• Summit is the highest point or apex of a volcano.
• Throat is the entrance of a volcano.
• Ash cloud is expelled in the atmosphere; volcanic ash or ash cloud is composed of pulverized rock and glass created during eruption.
• Volcanic bombs are the chunks of lava blasted into the air ehich solidify before reaching the ground.
• Volcanic bombs sizes may vary and can measure up to what mm in diameter?

  64 mm in diameter
• Pyroclastic flow are fast moving currents of hot gases and rock traveling downhill from a volcano.
• Tephra fall refers to fragmented material that consists of pumice, scoria, lithic materials, or crystals, or combination of the four.
• Lahar also called mudflows are flowing mixture of volcanic debris and water.
• Lahar are classified as primary or hot which are directly associated with volcanic eruption or as i cold lahar when they are caused by heavy rainfall.
• Volcano is an opening on Earth's surface where molten rock, gases, and other pyroclastic materials are ejected through the crust.
• According to plate tectonics theory, convection currents in the mantle triggers the movement of the plate boundaries which eventually causes volcanic eruptions and earthquakes near or along the edges of the plates.
• Pumice flow, ash flow, block and ash flow, glowing erupting cloud called nuee ardent
• Particle less than 2 mm diameter are called ash
• 2-64 mm are called lapilli
• Bigger than 64 mm in diameter are called blocks and bombs.
• Magma Temperature is the higher the temperature of magma, the lower the its viscosity.
• Chemical Composition is the magma with high silica content are more viscous than those with low silica content.
• Amount of Dissolved gases is the gas dissolved in magma tends to increase its ability to flow.
• Low silica and High gas can form a cinder cone volcano.
• High silica and High gas can form a composite volcano
• Low silica and Low gas can form a shield volcano
• High silica and low gas can form a lava dome volcano
• Phreatic is a steam-driven eruption as the hot rocks come in contact with water.
• Phreatomagmatic is a violent eruption due to contact between water ang magma.
• Strombolian is a periodic weak to violent eruption characterized by fountain lava.
• Vulcanian is characterized by loud and tall eruption columns that reaches up to 20 km high with pyroclastic flow and ashfall tephra.
• Plinian is an excessively explosive type of eruption of gas and pyroclastic.