M7.4 earthquake south of the Kermadec Islands

Thursday, June 18, 2020, 12:49:53 UTC · 33.293°S, 177.857°W

A magnitude 7.4 earthquake struck south of the Kermadec Islands on Thursday, June 18, 2020, 12:49:53 UTC, at a depth of 10.0 km (shallow). USGS received 47 “Did You Feel It?” reports, with a maximum reported intensity of VII (very strong). The USGS PAGER alert is green: low likelihood of casualties and damage. It is the strongest earthquake within 300 km since an M7.4 on May 16, 2006.

Tsunami flagUSGS sets this flag for large events in oceanic regions so tsunami warning centers review them. It does not by itself mean a tsunami occurred. Check tsunami.gov and local authorities for official messages.

Magnitude: 7.4; Major · mww
Depth: 10 km; Shallow
Felt reports: 47; Max intensity VII
Est. shaking: VII; Very strong (ShakeMap)
PAGER alert: Green; Impact estimate
Tsunami: Flag; Check tsunami.gov

Outlined circle: this earthquakeDashed circle: 200 km aftershock search areaColoured lines: estimated shaking intensity (USGS ShakeMap)

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

0 km

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

Depth: shallow

10 km

Shallow earthquakes (under 70 km) produce the strongest surface shaking for their size, so they are the ones most likely to cause damage near the epicenter.

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
Whangamata, Waikato, New Zealand	VII · Very strong	14	718 km
Palmerston North, Manawatu-Wanganui, New Zealand	III · Weak	5	977 km
Whakatane, Bay of Plenty, New Zealand	III · Weak	4	699 km
Opotiki, Bay of Plenty, New Zealand	III · Weak	3	690 km
Gisborne, Gisborne, New Zealand	III · Weak	3	702 km
Wellington, Wellington, New Zealand	II · Weak	3	1101 km
Hastings, Hawkeʿs Bay, New Zealand	III · Weak	2	850 km
Porirua, Wellington, New Zealand	III · Weak	2	1086 km
Kapiti, Wellington, New Zealand	III · Weak	2	1057 km
Lower Hutt, Wellington, New Zealand	III · Weak	2	1087 km
Napier, Hawkeʿs Bay, New Zealand	IV · Light	1	834 km
Te Kaha, Bay of Plenty, New Zealand	III · Weak	1	638 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 populated area was estimated to feel noticeable shaking.

After the main event

Aftershocks within 200 km

USGS lists 147 M2.5+ earthquakes within 200 km in the following 30 days; the largest was M5.5 on June 22, 2020. 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 1,348 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 5 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 · 282 km away
Limited damage (under $1M)tsunami
1978M7.7
S Of
9 Feb 1978 · 294 km away
2020M7.4
S Of, Raoul
18 Jun 2020 · 0 km away · intensity VII
tsunami
2019M7.2
S Of, Raoul
15 Jun 2019 · 278 km away
tsunami
2013M6.5
S Of, Raoul
30 Sep 2013 · 267 km away
tsunami

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

Nearby trackers