He spoke to a group of elderly people in Dannevirke, explaining what the centre does and the many geohazards in New Zealand.
"The reason that our centre exists is that New Zealand is, frankly, a rather dangerous place to live."
Up to 25,000 earthquakes can be experienced in New Zealand each year.
The reason for this, Rapley said, was that there were tens of thousands or even hundreds of thousands of faultlines all over the country.
Only Auckland and Otago were spared with fewer faultlines.
Rapley told the group that the centre has a lot of equipment out in the field, with about 300 stations in total, which allows the centre to monitor any activity – this includes earthquakes, volcanoes, tsunamis and landslides.
Part of their role in monitoring is to assess whether an event will be a problem.
"If it's a problem we go through a set of steps called a standard operating procedure where we finalise where it is, how big it is and we notify authorities, such as the National Emergency Management Agency.
"We escalate to a group of experts where they can convene and discuss if this poses a threat to New Zealand and this is all done as soon as possible."
Rapley said before the centre was created, even the experts were pretty much in the same boat as anyone else in terms of what happened in Kaikoura, which occurred just after midnight on November 14, 2016.
"When you get woken up and you don't know what's happening, but your house is shaking violently, that's pretty damn scary.
"Essentially you waste precious minutes because you don't know what's going on.
"Whereas now, we always have people who always have context with what's going on."
He said the monitoring centre could detect earthquakes happening far away from the country, for instance New Caledonia and know it was happening before it reached New Zealand.
Such earthquakes can lead to another threat, such as a tsunami.
Thanks to the information they receive from their monitoring, Rapley and his colleagues can calculate to a high degree the potential of a tsunami with this information then being passed on so alerts can be sent to those affected.
This was exactly what happened in March this year with the tsunami warnings in the Bay of Plenty after the earthquakes in the Kermadecs.
The centre is also able to monitor volcanoes, with seismometers measuring such activity as underground magma flow.
Rapley said there is an alert system whereby if there is very little activity the alert is at zero and increases when there is more likelihood of an eruption.
There are times when nothing is happening but the staff at the centre are always working on other projects.
Rapley said some of the staff have contributed to academic papers, while others work on personal projects, or upskilling by taking university courses.
They occasionally are able to go out into the field, for instance taking three-dimension scans of landslide dams.
These are where a landslide can block a river, creating a dam which eventually breaks through.
"It's pretty catastrophic," Rapley said.
They also participate in education programmes at schools and universities, giving talks on geohazards in the context of the locality.
Once a month the staff do what is called "high fidelity exercising".
"Stressful large events don't happen very often," Rapley said.
"To keep up our wits, we exercise events that have happened in the past and make them as real as we can."
