M7.4 earthquake in Kermadec Islands region

Tuesday, May 16, 2006, 10:39:23 UTC · 31.810°S, 179.307°W

A magnitude 7.4 earthquake struck in Kermadec Islands region on Tuesday, May 16, 2006, 10:39:23 UTC, at a depth of 152.0 km (intermediate). USGS received 44 “Did You Feel It?” reports, with a maximum reported intensity of VI (strong). It is the strongest earthquake within 300 km since an M7.5 on November 16, 1917.

Magnitude: 7.4; Major · mwb
Depth: 152 km; Intermediate
Felt reports: 44; Max intensity VI
Est. shaking: —; No ShakeMap
PAGER alert: None; Not issued
Tsunami: No flag; USGS feed

Outlined circle: this earthquakeDashed circle: 200 km aftershock search area

In context

How big was it, and why here?

Energy released

1.9 megatons of TNT

That is about 126 times the Hiroshima bomb. It released about 3,981 times the energy of a magnitude 5.0.

Tectonic setting

40 km

from the nearest mapped plate boundary, between the Kermadec and Australian plates. Earthquakes cluster along boundaries like this one, where plates collide, pull apart or slide past each other.

Depth: intermediate

152 km

Intermediate-depth earthquakes usually break inside a plate that is sinking into the mantle. Shaking spreads over a wide area but is gentler at the epicenter than a shallow quake of the same size.

Did You Feel It?

Where it was felt

Reports sent by people to USGS, grouped by place (most reports first). Intensity uses the Modified Mercalli scale (I–X): what people felt, not the magnitude.

Place	Intensity	Reports	Distance
Wellington, Wellington, New Zealand	III · Weak	16	1186 km
Christchurch, Canterbury, New Zealand	III · Weak	5	1489 km
Auckland, Auckland, New Zealand	VI · Strong	3	796 km
Gisborne, Gisborne, New Zealand	III · Weak	3	812 km
Wanganui, Manawatu-Wanganui, New Zealand	III · Weak	3	1047 km
Palmerston North, Manawatu-Wanganui, New Zealand	II · Weak	3	1063 km
Napier, Hawkeʿs Bay, New Zealand	II · Weak	3	931 km
Kapiti, Wellington, New Zealand	III · Weak	2	1141 km
Masterton, Wellington, New Zealand	IV · Light	1	1120 km
Opotiki, Bay of Plenty, New Zealand	III · Weak	1	776 km
Hastings, Hawkeʿs Bay, New Zealand	III · Weak	1	948 km
Tauranga, Bay of Plenty, New Zealand	III · Weak	1	789 km

I felt it — report to USGS ↗

USGS PAGER estimate

Who was exposed to shaking

USGS publishes PAGER impact estimates for significant earthquakes, usually within an hour. No PAGER estimate is available for this event.

After the main event

Aftershocks within 200 km

USGS lists 24 M2.5+ earthquakes within 200 km in the following 30 days; the largest was M5.1 on May 29, 2006. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.

Time after the mainshock on a logarithmic scale (first hours stretched), magnitude on the vertical axis. M2.5+ events from USGS.

Regional history

Past M5+ earthquakes within 300 km

USGS lists 1,328 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:

History · NOAA

Deadliest earthquakes in this area

NOAA’s significant-earthquake database lists 4 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700. The most severe:

1968M7.3
S Of, Raoul
25 Jul 1968 · 142 km away
Limited damage (under $1M)tsunami
1976M7.8
Kermadec Islands
14 Jan 1976 · 289 km away · intensity VIII
1978M7.7
S Of
9 Feb 1978 · 224 km away
1943M7.6
S Of
14 Sep 1943 · 298 km away

NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.

Nearby trackers