Date | November 2018 | Marks available | 2 | Reference code | 18N.2.bp.8 |
Level | SL and HL | Paper | 2 | Time zone | |
Command term | Outline | Question number | 8 | Adapted from | N/A |
Question
Outline the main features of one scale used to measure the magnitude of one named hazard type.
Describe what is meant by hazard risk.
Explain two ways in which people’s vulnerability to a tectonic hazard may be reduced.
Examine why some hazard events are more predictable than others.
Markscheme
Award [1] for the identification of a suitable scale (eg Richter, Momentum magnitude, VEI, Saffir–Simpson, drought intensity index) and [1] for further development.
For example: the Richter scale is used to measure the magnitude of an earthquake [1]. It is a logarithmic scale [1].
Risk is the probability of a hazard event [1] causing harmful consequences to people and the environment [1].
Award [1] for the identification of a suitable way/method, and [2] for further development and/or exemplification.
Possible ways include: land-use planning (zoning); insurance; aid; escape routes, building design, warning systems.
For example: Near active volcanoes, land-use planning [1] by drawing maps of areas likely to be affected by lava and ash flows [1] and then restricting development and human access to vulnerable areas [1].
Accept tsunamis as a tectonic hazard.
There are three different aspects to hazard prediction: location, timing and magnitude. These can be examined in relation to a single type of hazard, or more than one type of hazard.
The general location of most hazards can be predicted by examining historical patterns of occurrence, and relationships to physical factors. For example, the location of earthquakes and volcanic activity can be monitored and mapped, and these can be related to processes at plate margins. Patterns of droughts and hurricanes may also be related to atmospheric conditions.
The timing and magnitude of hazards are much harder to predict than location. Volcanic hazards may be easier to predict, for example by using instrumentation to measure ground movements and gas emissions. The time of occurrence and the strength of earthquake hazards are almost impossible to predict with current technology. Although difficult to predict before they have formed, the timing and magnitude of atmospheric hazards such as hurricanes can be predicted with degrees of certainty as they develop.
For all hazards, examination of past records of timing and magnitude of events can help calculate the recurrence intervals of hazard events of a certain magnitude. However, reliability of probability analysis depends on the length and accuracy of previous records; it is often difficult to predict the occurrence of high magnitude/low frequency events.
Good answers will examine the effectiveness of the three elements of hazard prediction with reference to different hazard events. They might examine whether tectonic hazards are more reliably predicted than atmospheric hazards. Accurate prediction depends on collection of accurate data and a full understanding of geophysical and atmospheric processes. This might be easier in some cases than others. However, there will always be an element of uncertainty and risk.
At band D, expect a description of some reasons why some hazard events are more predictable than others.
At band E, expect either a more detailed explanation of why some hazard events are more predictable (which may include methods of prediction and their relative accuracy), or some examination of the concept of predictability.
At band F, expect both.
Marks should be allocated according to the Paper 2 markbands (available under the "Your tests" tab > supplemental materials).