The Pacific ring of fire made itself felt with two small earthquake jolts about 15 minutes apart, generated 70km off the Tutukaka Coast yesterday morning.
A number of people between Ngunguru and Matapouri noticed the earth move but the event went unnoticed by many thousands living or holidaying on the coast.
GeoNet, the agency which records seismic activity, classified both as ''unnoticeable earthquakes''.
GeoNet reported the first ''unnoticeable'' jolt at 8.05am; magnitude 3.7, 5km deep, 70km east of Whangarei. The second was at 8.20am; magnitude 2.6 and also 5km deep.
Both quakes were caught on seismic recorders at Waipu Caves.
Will Trusewich posted on the Tutukaka Coast community Facebook site that he felt the first quake while lying down, and the bed moved ''north and south''.
But it wasn't earthquakes that had Dive Tutukaka rocking, according to co-owner Kate Malcolm.
''The ground's been shaking here all morning but it's from the number of people coming in and out. We've been really busy, and no, I didn't feel a thing,'' Malcolm said.
Although it is rare for earthquakes to be felt above ground in Northland, at least 40
small jolts were recorded throughout New Zealand in a 10-hour period from midnight yesterday — which is nothing out of the ordinary.
Northland, with no known active seismic faults, has the lowest earthquake risk in the country.
Although earthquakes are occasionally felt in the region none have been greater than 5 on the Richter scale, and most have been centred far away. Most also fall into the ''unnoticeable'' category.
However, a series of quakes rocked the Far North, causing damage to several properties and enough ground-sway to empty water tanks, in December 1963. Since then, noticeable earthquakes included two under magnitude 4.5 in April and September 1964, a belter that shook the ground around Maungaturoto in 1978 and a magnitude 4.3 quake in 1995.
In December 2003, Maungaturoto and surrounds were again shaken by 4.4 scale earthquake at a depth of 12km, and a swarm of six small earthquakes occurred near Takou Bay in September 2006.
Northland was largely created by volcanic activity and of rocks that were broken and fractured during a 22-million year creep southwest after tectonic plate activity on the seafloor about 100km northeast of Whangarei.