GeoNet's iPhone app has been out a week and the early feedback on its Facebook site is positive.
The latest free app follows the launch of a similar product for Android phones and ongoing testing of the GeoNet Rapid website, which can give a reasonably accurate fix on earthquake locations and magnitudes within seconds.
GeoNet is a joint project between GNS Science and the Earthquake Commission to build and operate a modern geological hazard monitoring system.
GeoNet spokesman Kevin Fenaughty said there had been a lot of interest in the smartphone apps.
"Straight after the release of the GeoNet Quake for Android app, we had lots of enquiries for an iPhone version. This was something we always planned to do during the year and this response was encouraging."
Australian software experts developed the system and trained GeoNet staff.
"The iPhone users currently have an advantage over the Android users, as their earthquake notifications are `pushed' to the iPhone whenever an alert meeting their own settings arises," Fenaughty said.
"We will be adding this functionality to Android later this year – it currently uses 'pull' technology, so checks the earthquake lists at a regular time interval tailored by the user instead."