Reviewed by USGS40y ago
M5.0 earthquake south of the Kermadec Islands
Saturday, March 7, 1987, 07:57:01 UTC · 33.239°S, 179.855°W
A magnitude 5.0 earthquake struck south of the Kermadec Islands on Saturday, March 7, 1987, 07:57:01 UTC, at a depth of 93.4 km (intermediate). It is the strongest earthquake within 300 km since an M5.4 on February 19, 1987.
- Magnitude
- 5.0
- Moderate · mb
- Depth
- 93 km
- Intermediate
- Felt reports
- 0
- Did You Feel It?
- Est. shaking
- —
- No ShakeMap
- PAGER alert
- None
- Not issued
- Tsunami
- No flag
- USGS feed
Outlined circle: this earthquakeDashed circle: 75 km aftershock search area
In context
How big was it, and why here?
Energy released
477 tons of TNT
That is about 1/32 of the Hiroshima bomb. Each whole step in magnitude is about 32 times more energy.
Tectonic setting
51 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
93 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
No “Did You Feel It?” reports have been published for this event yet. If you felt it, you can add your report on the USGS website.
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 75 km
USGS lists 1 M2.5+ earthquake within 75 km in the following 30 days; the largest was M4.7 on March 24, 1987. 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 418 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 6.9south of the Kermadec IslandsSeptember 26, 1985 · 196 km SE of this epicenter
- 6.9south of the Kermadec IslandsJuly 11, 1943 · 178 km NE of this epicenter
- 6.8south of the Kermadec IslandsFebruary 17, 1987 · 71 km NE of this epicenter
- 6.8south of the Kermadec IslandsJanuary 8, 1970 · 219 km SW of this epicenter
- 6.7south of the Kermadec IslandsFebruary 13, 1949 · 199 km E of this epicenter
- 6.6south of the Kermadec IslandsAugust 23, 1986 · 166 km SW of this epicenter
- 6.6south of the Kermadec IslandsSeptember 1, 1937 · 76 km NE of this epicenter
- 6.5Kermadec Islands, New ZealandAugust 21, 1968 · 285 km N of this epicenter