DRRR

• Volcanic Hazard - Refers to any potential dangerous volcanic process (lava flow, pyroclastic flow, ash, etc)
• Volcano - opening/vent on earth’s surface where molten rocks, gases, and ashes are ejected.
• Shield Cone - Continuous lava flows coming from the vent
• Cinder Cone - Simplest type and forms from
• Composite Volcano - Often steep side, closely symmetrical (almost perfect)
• Active Volcano -  Often steep side, closely symmetrical (almost perfect)
• Erupting - explosive or quiet
• Dormant - no attempt within 10,000 years
• Extinct - not erupted for more than 10,000 years
• Extinct - not had an eruption, like Mt. Pinatubo before its eruption in 1991
• Lava Flow - can be fluid or viscous
• Fluid - fast, low, silica, high temp
• Viscous - slow, high silica, low temp
• Visocus - molten magma that can reach 1093 C
• Pahoehoe - lava flow that is highly fluid, creating a smooth and ropy texture when they harden
• Aa - slow and more viscous, blocky, and jagged appearance
• Volcanic Gases - water vapor and CO2 makes up bulk compositions of volcanic gases + sulfur dioxide,+hydrogen chloride & hydrogen fluoride can also be added.
• Volcanic Gases - most common viscous acts before, during, and after a volcanic eruption
• Pyroclastic Flows - hot, dry, turbulent mass mixtures of different pyroclastic materials and gases that move downward along a slope at a speed that can go up to several 100mps.
• Soul Friere - from collapse of a high vertical column
• Soul Friere - from collapse of a high vertical column
• Merapi - lava dome grows too steep; gravitational
• Tephras - fragments of volcanic materials
• Ash - less than 2mm
• Lapili - 2-64mm
• Blocks and Bomb - more than 64mm
• Ballistic Projectiles -large tephras that leave the volcanic vent
• Lahar - when tephras mix with water and form a slurry
• Primary Lahar - form when pyroclastic flows occur along bodies of water
• Secondary Lahar - formed after eruption
• Basal Flow - course pyroclastic materials
• turbulent ash - cloud riding over basal flow
• Pyroclastic Surge - Have lower density and are more mobile than pyroclastic flows because of higher ratio of gas to tephra