Forecasts and predictions, what’s the difference?

Published: Fri Oct 5 2018 12:00 PM

This is the first in a three-part series on earthquake forecasting. We will also be sharing how and why we make earthquake forecasts, so check back for that soon.

The difference between earthquake forecasts and earthquake predictions can be confusing. Here’s our low down…

An earthquake forecast provides a probability or chance. It says how likely it is that an earthquake of a given magnitude range within a given area, over a given time frame, could happen.

An earthquake prediction would be much more specific. It would say that an earthquake of a certain magnitude in a certain area, at a certain time, will happen.

At present there is no scientific way anywhere in the world to accurately and reliably predict exactly when and where an earthquake is going to happen

Earthquake forecast vs prediction

Earthquake forecast vs prediction

We would all like more certainty around what is going to happen in the future, especially when we are stressed or scared. Although we can’t yet predict earthquakes, what we can do is accurately and reliably forecast earthquakes. Forecasts are useful as they tell us what is likely and, importantly, what is not likely to happen. Forecasts allow us each to make informed decisions, like whether we want to stay or go if there’s a possibility of another big quake or aftershock. It can also inform more simple things like when we might decide to put precious items back up on shelves after a big earthquake. This is why we publish aftershock forecasts on our website after big earthquakes.

We understand that some people will be nervous when they learn of a damaging quake or feel one. That’s normal. If you are anxious about earthquakes and this is affecting your ability to go about your daily life the All Right? website and hotline (specifically for Cantabrians - 0800-777-846) are great resources where you can read and talk about any concerns that you have regarding earthquakes.

Whatever the forecast, knowing your neighbours and taking a few minutes to work out what you would do with no power, communications or transport for a few days will make a big difference to how you and your community cope after an earthquake or any emergency. There are some great ideas at happens.nz.

Attributable to Dr Matt Gerstenberger Seismologist, GNS Science.