Hazards

Question 1

Geophysical

Answer 1

A geophysical hazard is potentially damaging natural event encompassing geologic or geomorphological activity, which may cause the loss of life, injury, property damage, social and economic disruption, or environmental degradation. An example is a seismic event such as earthquakes.

Question 2

Atmospheric

Answer 2

An atmospheric hazard is a potentially damaging natural event that is caused due to an atmospheric process. Examples could be wildfires or tropical storms (shared between atmospheric and hydrological as both events need to be present.)

Question 3

Hydrological

Answer 3

A hydrological hazard is a potentially damaging natural event which is caused due to an abnormality of process within water- be it lakes, rivers, oceans etc. Examples include tropical storms (shared between hydrological and atmospheric as both events need to be present.)

Question 4

Fatalism

Answer 4

An attitude or viewpoint that people can’t shape the outcome of a hazard. Represents an ‘acceptance’ of the probability of being involved in a natural disaster and risk involved as such but no further actions are viewed as necessary. Nothing can be done to mitigate against the risk- little or no preventative measures are put in place ‘gods will’

Question 5

Adjustment/adaptation

Answer 5

Responding to or altering one’s designs or protocols to help reduce the impact of a natural hazard.

Question 6

Mitigation

Answer 6

A perception that hazards can be measured and are predictable. Through engineered soloutions and or technology they can be controlled and effects reduced.

Question 7

Crustal evolution

Answer 7

The natural geological processes of fomation, destruction and renewal of the outer shell of Earth’s surface through plate tectonic movement and resulting effects such as seafloor spreading.

Question 8

Gravatitional sliding/ridge push

Answer 8

A proposed driving force for plate motion in plate tectonics that occurs at mid-ocean ridges as the result of the rigid lithosphere sliding down the hot, raised asthenosphere below mid-ocean ridges.

Question 9

Slab pull

Answer 9

The pulling force exerted by a cold, dense oceanic plate plunging into the mantle due to its own weight. The theory is that because the oceanic plate is denser than the hotter mantle beneath it, this contrast in density causes the plate to sink into the mantle.

Question 10

Convection currents

Answer 10

-Theory where very hot material at the deepest part of the mantle rises, cools, and sinks before being heated again. repeating the cycle over and over. this spreads at its farthest point from Earth’s core, pushing the above plates with it, leading to tectonic plate movement.

Question 11

Seafloor spreading

Answer 11

A process that occurs at mid-ocean ridges, where new oceanic crust is formed through volcanic activity and then gradually moves away from the ridge, can be observed through paleomagnetism.

Question 12

Continental drift

Answer 12

A theory that explained how continents shift position on Earth’s surface, set in 1912 by Alfred Wegener, a geophysicist and meteorologist, continental drift also explained why look-alike animal and plant fossils and similar rock formations are found on different continents.

Question 13

Seismicity

Answer 13

A study in geophysics and measure encompassing earthquake occurrence, mechanisms and magnitude at a given location.

Question 14

Vulcancity

Answer 14

The process through which gases and molten rock are either extruded on the earth’s surface or intruded into the earth’s crust.

Question 15

Magma plumes

Answer 15

In areas of hot, upwelling mantle, a hot spot develops above the plume in the crust. Magma generated by the hot spot rises through the rigid plates of the lithosphere and produces active low-viscosity volcanoes at the Earth’s surface. These can lead to deep sea trenches or island arcs.

Question 16

Lava flows

Answer 16

A moving outpouring of lava, created during a non-explosive effusive eruption. When it has stopped moving lava solidifies to form igneous rock.

Question 17

Lahars

Answer 17

A flow of wet material down the side of a volcano consisting of erupted ash and water. Found when heavy rainfall occurs after a volcanic eruption- essentially they are volcanic mudflows

Question 18

Pyroclastic flow

Answer 18

A fast-moving current of hot gas and volcanic matter (collectively known as tephra) that moves away from a volcano at 100km/h on average reaching up to 700 km/h

Question 19

Gases/acid rain

Answer 19

Volcanoes exhaust dangerous gases such as sulphur dioxide reacts with water molecules, acidifying them and producing acid rain when dropped.

Question 20

Tephra

Answer 20

Fragmental material produced by a volcanic eruption regardless of composition, fragment size, or emplacement mechanism. Volcanologists also refer to airborne fragments as pyroclastic flows.

Question 21

Spatial distribution

Answer 21

In this case, of a natural event, represents the geographical spread of results or data

Question 22

Magnitude

Answer 22

The size of a hazard- how powerful or damaging it is

Question 23

Frequency

Answer 23

Represent how often or the assumed likelihood of an event occurring

Question 24

Shockwaves

Answer 24

When an earthquake occurs, it produces seismic shockwaves, two types can travel through earth’s interior- P (primary) or S (secondary), they both move in different ways, outwards from the hypocentre (focus).

Question 25

Liquefaction

Answer 25

Occurs when vibrations or water pressure within a mass of soil cause the soil particles to lose contact with one another. As a result, the soil moves like a liquid, cannot support weight and can flow down very gentle slopes.

Question 26

Landslides

Answer 26

The movement downslope of a mass of rock, debris, earth or soil. Occur when gravitational and other types of shear stresses within a slope exceed the shear strength of the materials that form the slope.

Question 27

Natural and human agency

Answer 27

A Geographical term to describe the two ways a hazardous environment can occur- through natural events or human activity, which through direct (arson) and indirect (enhanced greenhouse effect) can affect these events.

Question 28

Resilience

Answer 28

A determination, or strength if character or community to pull through and counteract any disastrous events which could have had human consequences.

Question 29

Hazard

Answer 29

A threat (whether natural or human) that has the potential to cause loss of life, injury, property damage, socio-economic disruption or environmental degradation.

Question 30

Hazard event

Answer 30

The occurrence (realisation) of a hazard, the effects of which change demographic, economic and/ or environmental conditions

Question 31

Disaster

Answer 31

A major hazard event that causes widespread disruption to a community or region, with significant demographic, economic and or environmental losses, and which the affected community is unable to deal with adequately without outside help.

Question 32

Vulnerability

Answer 32

The geographic conditions that increase the susceptibility of a community to a hazard or to the impacts of a hazard event

Question 33

Risk

Answer 33

The probability of a hazard event causing harmful consequences (expected losses in terms of death, injuries, property damage, economy and environment)

Question 34

Areal extent

Answer 34

The size of the area covered by the hazard.

Question 35

Speed of onset

Answer 35

The time difference between the start of the event and the peak of the event

Question 36

Factors affecting earthquake damage

Answer 36

-Strength and depth of earthquake and number of aftershocks
-Population density
-Type of buildings (HICs have better quality buildings, more emergency services and the funds to cope and more likely to have insurance cover)
-Distance from the epicentre
-Economic development- level of preparedness, effectiveness of emergency response services, access to technology, quality of health services
-Secondary hazards- mudslides, tsunamis, water contamination, hunger, disease

Question 37

What is the difference between hazards and disasters?

Answer 37

-A hazard is a perceived natural event which threatens both life and property, a disaster is the realisation of this hazard

Question 38

Why do the poor often live in hazardous environments?

Answer 38

-The constraints placed on the poor people by the prevailing social and political system of the country often mean that poor people live in unsafe areas such as steep slopes or floodplains, as they are prevented from living in better areas.