CHAPTER 15: GEOHAZARDS - VOLCANOS/EARTHQUAKES

Question 1

What is a tsunami?

Answer 1

large wave triggered by earthquake or natural disturbance of ocean floor

Question 2

What is a geohazard?

Answer 2

A hazard posed to people by physical earth

Question 3

define volcano

Answer 3

Conical, circular structure built by accumulation of lava flows and tephra

Question 4

tephra is…

Answer 4

volcanic ash

Question 5

Volcanos that have erupted in the last 10000 years and could erupt again are called

Answer 5

Active Volcanos

Question 6

Volcanos that have not erupted for 10000 years but could awaken are called

Answer 6

Dormant volcanos

Question 7

Volcanos that have not eruptd for tens of thousands of years and can never erupt again are called

Answer 7

Extinct volcanos

Question 8

What are statovolcanos?

Answer 8

comosite, typical

Question 9

What are shield volcanos?

Answer 9

most massive underwater, hawaii

Question 10

qWhat are Cinder cones?

Answer 10

volcanos smaller, loose debris

Question 11

Lava domes are.

Answer 11

volcanos

Question 12

Strato volcanos are composed of alternating layers of…

Answer 12

lava and pyroclasts

Question 13

Shield volcanos are composed of layers of..

Answer 13

basaltic

Question 14

Cinder cones are made of entirely

Answer 14

Pyroclast material

Question 15

The angle of repose refers to..

Answer 15

the steepest angle at which loose sediments can settle

Question 16

Lava domes are formed from

Answer 16

Thick lava that solidified

Question 17

What are the 3 types of Volcanic products?

Answer 17

Lava, pyroclasts, gases

Question 18

The hottest lava is

Answer 18

Mafic temp 1000-1200

Question 19

Viscosity of magic lava is..

Answer 19

low, flows easily

Question 20

Felsic lava’s viscosity is

Answer 20

High! does not flow easily

Question 21

Mafic lava is found in which volcano?

Answer 21

Shield

Question 22

Felsic lava is found in which volcano?

Answer 22

Lava dome

Question 23

4 types of pyroclasts:

Answer 23

1. ash
2. lapilli
3. bombs
4. blocks

Question 24

What is the most abundant volcanic gas?

Answer 24

Water vapour

Question 25

What is a caldera?

Answer 25

a large crater formed from volcanic explosion or by collapse of volcanic cone

Question 26

2 types of volcanic erruptions

Answer 26

1. effusive

2. explosive

Question 27

Effusive eruptions are..

Answer 27

nonexplosive, produce mostly lava

Question 28

Explosive eruptions are

Answer 28

send rock, ash, gas high into troposphere or statoo

Question 29

Volcanic Explosivity index ranks..

Answer 29

volcanic eruptions based on materials ejected during eruption

Question 30

What are lahars?

Answer 30

Volcanic mudslide

Question 31

What are pyroclastic flows?

Answer 31

Quick moving avalanche of gas and ash

Question 32

3 types of faults

Answer 32

1 norma
2 reverse
3 strike-slip

Question 33

the initial movement along a fault during an earthquake is called the..

Answer 33

focus or hypocentre

Question 34

the location on the grounds surface immediately above the focus of an earthquake where intensity is greatest

Answer 34

epicentre

Question 35

Body waves in earthquakes are

Answer 35

compressional and shear

Question 36

what is a seismograph?

Answer 36

instrument used to detect, measure, and record earthquakes

Question 37

earthquake intensity is measured by…

Answer 37

Modified Mercalli Intrensity Scale: amount of damage caused to physical structures…1-12

Question 38

The Moment Magnitude Scale mesures earthquake intensity on…

Answer 38

ground movement

Question 39

What is liquefaction

Answer 39

transformation of solid sediments into unstable bay ground shaking