ELS module 3

Question 1

beyond human control.

Answer 1

NATURAL HAZARD

Question 2

due to accidents, carelessness or inability to implement

protective measures.

Answer 2

HAZARDS INDUCED BY HUMANS

Question 3

because of personal and political interests.

Answer 3

PLANNED BY PEOPLE

Question 4

is the process of recognizing hazards that
may arise from a system or its environment, documenting
their unwanted consequences and analyzing their
potential causes.

Answer 4

Hazard analysis

Question 5

the term signifies a
vent, hill,
or mountain from which
molten or hot
rocks with gaseous
materials are ejected.

Answer 5

volcano

Question 6

´ Takes place when two plates converge.

Answer 6

Subduction

Question 7

Takes place when volcanic gases accumulate and
the pressure becomes too great inside the magma
chamber. The volcano then expels lava, rocks, ash
and gas.

Answer 7

Volcanic eruption

Question 8

– currently erupting or is showing
signs of volcanic eruption. Erupted within
the last 600 years

Answer 8

Active

Question 9

– is one which has
erupted and then entered a long period
of inactivity

Answer 9

Potentially active

Question 10

one that has not shown any
sign of activity for a long period. It has no
record of volcanic eruption in the past
thousand years.

Answer 10

Inactive

Question 11

mass of magma that flows down the slope of the

volcano at a rate of 3 kilometers per day

Answer 11

Lava flow

Question 12

refers to hot dry masses of fragmented volcanic
materials that move along the slope and in contact with ground
surface at a speed greater than 60 kilometers per hour.

Answer 12

´ Pyroclastic flow

Question 13

are showers of fine to coarse-grained volcanic

materials and other airborne products of a volcanic eruption.

Answer 13

Tephra falls

Question 14

– are rocks that are released into the air by an

erupting volcano.

Answer 14

Ballistic projectiles

Question 15

one of the basic components of magma or lava.
Active and inactive volcanoes may release gases to the
atmosphere in the form of water vapor, hydrogen sulfide, sulfur
dioxide, carbon monoxide, carbon dioxide, hydrogen chloride
and hydrogen fluoride.

Answer 15

Volcanic gas

Question 16

– flowing mixture of volcanic debris and water. It is classified
into two:
´ Primary of hot lahar
´ Secondary or cold lahar

Answer 16

´ Lahar

Question 17

• explosion driven by steam
  produced by heating and expansion of
  groundwater due to an underlying hot
  source.

Answer 17

Phreatic

Question 18

• eruption resulting from
  the ejection of magmatic gases and steam
  produced by the conversion of groundwater
  to steam by ascending magma, mixed with
  water, fine ash and variably-sized volcanic
  bombs fragmented from the pre-existing
  rock formations, and fresh magmatic ejecta

Answer 18

Phreatomagmatic

Question 19

weak to violent eruption characterized by lava fountaining and
effusion of molten lava. Typical ejecta are ovoid and fusiform bombs and scoria
(cinders). Ash is relatively minor in amount and eruption cloud is generally yellowish
to white in color

Answer 19

Strombolian

Question 20

eruption resulting from the release of large quantities of
accumulated magmatic gas which lefts fine ashes and blocks coming
from the magma with great force high in the air forming voluminous
eruption clouds.

Answer 20

Vulcanian

Question 21

eruption caused by the release of large
quantities of gas from an extremely viscous
magma that hurls out ash and other pyroclastic
materials and is characterized by the presence of
nuee ardente or glowing avalanche consisting of
hot gases

Answer 21

Peleean

Question 22

• eruption of great violence characterized by voluminous explosive
  ejections of pumice and pyroclastic flows. The extrusion of gas-rich magma is
  commonly accompanied by collapse of the top of the volcanic cone forming a
  caldera.

Answer 22

Plinian