30 Questions
What is the characteristic of lahars when they are most dangerous?
When they are wet and fluid
What is the primary reason why ash fall poses a great danger to airplanes?
Ashes can interfere with the plane's engines
What is the result of excessive ash fall on crops?
Crops are destroyed
What is the term used to describe the collective materials that come out of the volcano's mouth during an explosive eruption?
Pyroclastic Flow
What is the effect of ash fall on the environment?
It causes both breathing problems and climate cooling
What is the composition of ash fall?
Fine-grained volcanic materials
What is the term for molten materials that come out of the surface during a volcanic eruption?
Lava
How are active volcanoes classified by PHIVOLCS?
Erupted within historical times and have documented records
What is the term for a type of mudflow or debris flow that forms when pyroclastic materials mix with rainwater or water from a volcano's crater lake?
Lahar
What is the term for various forms of matter ejected by a volcano during its eruption?
Pyroclastic materials
What is the term for a vent on the earth's crust where magma moves up from the depths of the earth to its surface and into the atmosphere?
Volcano
What type of volcano has a physical form that is being changed by agents of weathering and erosion?
Inactive volcano
What is radon?
A type of noble gas
What occurs prior to an earthquake event?
An increase in radon emissions in soils and groundwater
What is the term used to describe a series of mild local movements that occur frequently at short periods of time at almost similar depths?
Swarms
What is the main difference between landslides and slope failure?
The type of process involved (mass-wasting or failure)
What is an aquifer?
A type of rock that contains groundwater
What is the purpose of studying earthquake trends?
To predict when the next big earthquake will occur
What is the primary cause of seismic waves during an earthquake?
The release of energy stored in the earth's rocks
What is the term used to describe the breaking or fracture of the earth's surface or rocks?
Ground rupture
What is the result of the increase in water pressure in the soil during an earthquake?
The reduction of effective stress between solid particles
What is the term used to describe the process of the ground sinking or developing a depression due to liquefaction?
Subsidence
What is one of the effects of liquefaction?
Ground subsidence
What can be formed as a result of the process of subsidence?
Lakes
What is the maximum speed that pyroclastic flows can travel?
700 kph
What is the temperature range of rocks and gas inside pyroclastic flows?
200°C to 700°C
What is the primary factor that affects the direction of pyroclastic flows?
The topography of the surrounding area
What is the term used to describe the turbulent rush of pyroclastic materials above the pyroclastic flow?
Pyroclastic surge
What is the minimum size of rock fragments that are classified as blocks or bombs?
64mm
What was the approximate number of inhabitants killed when Mt. Pelee erupted on May 8, 1902?
30,000
Learn about the process of volcanic eruptions, the movement of magma, and the classification of volcanoes. This quiz covers the basics of volcanic activity, including active and inactive volcanoes, and the role of PHIVOLCS in monitoring volcanic activity.
Make Your Own Quizzes and Flashcards
Convert your notes into interactive study material.
Get started for free
