M6.1 earthquake in Kermadec Islands, New Zealand

Friday, September 27, 2019, 12:05:02 UTC · 30.173°S, 177.863°W

A magnitude 6.1 earthquake struck in Kermadec Islands, New Zealand on Friday, September 27, 2019, 12:05:02 UTC, at a depth of 34.0 km (shallow). USGS received 3 “Did You Feel It?” reports, with a maximum reported intensity of IV (light). The USGS PAGER alert is green: low likelihood of casualties and damage. It is the strongest earthquake within 300 km since an M6.3 on June 27, 2019.

Magnitude: 6.1; Strong · mww
Depth: 34 km; Shallow
Felt reports: 3; Max intensity IV
Est. shaking: IV; Light (ShakeMap)
PAGER alert: Green; Impact estimate
Tsunami: No flag; USGS feed

Outlined circle: this earthquakeDashed circle: 100 km aftershock search areaColoured lines: estimated shaking intensity (USGS ShakeMap)

In context

How big was it, and why here?

Energy released

21 kilotons of TNT

That is about the energy of the Hiroshima bomb. It released about 45 times the energy of a magnitude 5.0.

Tectonic setting

123 km

from the nearest mapped plate boundary, between the Kermadec and Australian plates. Earthquakes this far from a boundary happen on faults inside a plate, often less frequently but sometimes strongly.

Depth: shallow

34 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
Auckland, Auckland, New Zealand	III · Weak	2	1015 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 100 km

USGS lists 11 M2.5+ earthquakes within 100 km in the following 30 days; the largest was M5.2 on September 27, 2019. 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 2,184 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 16 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700. The most severe:

1986M8.1
Raoul
20 Oct 1986 · 271 km away
Limited damage (under $1M)tsunami
1976M7.9
Kermadec Islands
14 Jan 1976 · 117 km away
Limited damage (under $1M)tsunami
1968M7.3
S Of, Raoul
25 Jul 1968 · 87 km away
Limited damage (under $1M)tsunami
1917M8.0
Kermadec Islands
1 May 1917 · 137 km away
tsunami
1976M7.8
Kermadec Islands
14 Jan 1976 · 68 km away · intensity VIII
1959M7.7
Kermadec Islands
14 Sep 1959 · 204 km away

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

Nearby trackers