Volcanic Eruptions - PREDICTING ERUPTIONS AND MINIMIZING RISKS Flashcards
Predictive Tools for Volcanic Eruptions
Geologic History;
Topographic Changes;
Seismic Monitoring;
Monitoring of Volcanic Gas;
Geophysical and GroundwaterChange
makes use of the size, shape, composition, and layering characteristics of the particles of a volcanic deposit to infer the history of a particular volcano
Geologic History
Geologic history makes use of the ____, ____, ____, and ____ characteristics of the particles of a volcanic deposit to infer its history
size, shape, composition, and layering characteristics
the presence of _____ commonly causes the volcano to swell or inflate
pressurized magma
accurately surveying changes in the shape of a volcano over time can give an idea to the _____ as well as the ____
position of the magma within a volcano ;
volume moving into the magma chamber
t or f: seismic monitoring of an volcano involves the use of seismometer
T
it is an excellent tool for predicting eruption as earthquake activity invariably increases as magma moves towards the surface
seismic monitoring
t or f: earthquake activity invariably increases as magma moves towards the surface
T
____ accumulates when rising magma forces its way through _____, creating what geologist call ______
strain ;
crustal rocks;
magmatic earthquakes
magmatic earthquakes are sometimes called:
harmonic tremors
harmonic tremors occur when magma pushes its way into the surface, the resulting earthquake vibrates in a _____ and _____ manner
steady and rhythmic
t or f: magmatic earthquakes have relatively high magnitudes and occur in distinct swarms
F (low magnitude)
t or f: magmatic earthquakes may last an hour or more compared to tectonic earthquakes that take place abruptly and last a minute or two at most
T
t or f: volcanic gases do not always originate from fresh magma moving up from depth
T
other sources of volcanic gases include ___ and _____
heated groundwater;
older magma leftover from a previous eruption
