Management to reduce the effects of a tectonic hazard

The way in which many places attempt to reduce the risk posed by hazards of any kind is to use all or a combination of the following:

Monitoring

This consists of the use of specific technologies to watch over areas which are particularly susceptible to tectonic events and to record certain types of data.

In the case of volcanoes, tiltmeters, for example, can be used to detect the changes in the level of the ground as some volcanoes are known to bulge before an eruption. Seismometers can also be used to detect movements of magma beneath the ground, gases can be monitored, as changes in these can indicate impending activity, and thermal imagery from satellites can be used to see if volcanoes are starting to heat-up. 

Earthquakes are a little trickier to monitor, as they often occur without warning. One of the keyways that scientists do try to monitor them, however, is by measuring tectonic plate movements.  This is undertaken by a network of GPS stations installed in tectonically active regions, which allows scientists to measure plate movements. Where plates continually move, it suggests tensions at plate boundaries are continuously relieved, preventing buildup and associated earthquakes. However, where plates may not seem to be moving, it might suggest they are locked, pressures are building, and that the potential for an earthquake could be increasing.

Gas sensors for both earthquakes and volcanoes are useful monitoring tools as radon gas increases and/or is released before an earthquake or volcanic eruption. 

Prediction 

Prediction works hand in hand with monitoring, with scientists taking the monitoring data and trying to work out what it shows. 

For volcanoes, what scientists look for are changes in the data that is being collected. For example, if a volcano starts to bulge, heats up, if gas emissions change or if the numbers of tremors increase, it might indicate that the volcano is becoming unstable and that an eruption is imminent.

Without clear indicators of impending earthquakes, their prediction is much more difficult, and scientists often prefer to use the term ‘forecast’. In such cases, scientists will take the data they have monitored, look at when past events have occurred, and then use this information to forecast when and where an earthquake might occur, usually over a long time period. For example, scientists might forecast that there is the chance of an earthquake occurring in a particular location, within the next 30 years. What shows more potential however, are Early Warning Systems (EWS). Once an earthquake happens, seismic waves are sent out from the focus, and the less-destructive P-waves shoot out at speed. If automated EWSs can detect these P-waves quickly enough, then they can send warnings out to people in the vicinity that the more destructive surface waves will be arriving imminently. Japan and Mexico have such systems in place, and they have been successfully used a number of times.