Magnitude7.3

Reviewed by USGSNew Zealand7y ago

M7.3 earthquake in Kermadec Islands, New Zealand

Saturday, June 15, 2019, 22:55:04 UTC · 30.644°S, 178.100°W

A magnitude 7.3 earthquake struck in Kermadec Islands, New Zealand on Saturday, June 15, 2019, 22:55:04 UTC, at a depth of 46.0 km (shallow). USGS received 12 “Did You Feel It?” reports, with a maximum reported intensity of VIII (severe). 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 October 21, 2011.

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
7.3
Major · mww
Depth
46 km
Shallow
Felt reports
12
Max intensity VIII
Est. shaking
VI
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

1.3 megatons of TNT

That is about 89 times the Hiroshima bomb. It released about 2,818 times the energy of a magnitude 5.0.

Tectonic setting

112 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

46 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.

PlaceIntensityReportsDistance
Auckland, Auckland, New ZealandIV · Light2955 km
Outram, Otago, New ZealandI · Not felt21975 km
Manutuke, Gisborne, New ZealandIV · Light1964 km
Kaiapoi, Canterbury, New ZealandII · Weak11632 km
Wellington, Wellington, New ZealandI · Not felt11344 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 163 M2.5+ earthquakes within 200 km in the following 30 days; the largest was M6.4 on June 19, 2019. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.

Regional history

Past M5+ earthquakes within 300 km

USGS lists 2,201 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 14 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700. The most severe:

  1. 1976M7.9

    Kermadec Islands

    14 Jan 1976 · 174 km away

    Limited damage (under $1M)tsunami

  2. 1968M7.3

    S Of, Raoul

    25 Jul 1968 · 34 km away

    Limited damage (under $1M)tsunami

  3. 1917M8.0

    Kermadec Islands

    1 May 1917 · 192 km away

    tsunami

  4. 1976M7.8

    Kermadec Islands

    14 Jan 1976 · 116 km away · intensity VIII

  5. 1959M7.7

    Kermadec Islands

    14 Sep 1959 · 261 km away

  6. 1978M7.7

    S Of

    9 Feb 1978 · 71 km away

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

Nearby trackers

Closest city pages