M5.9 earthquake Halmahera, Indonesia
A magnitude 5.9 earthquake struck in Halmahera, Indonesia on Wed, Apr 20, 1988, 5:48 AM GMT+9 (20:48 UTC), 75 km (47 mi) below the surface.
Map
Where this earthquake was located, with the others nearby. Select one for its page.
The earthquake
- Magnitude
- 5.9 (Mw, moment), moderate
- Magnitude from
- USGS National Earthquake Information Center
- Local time
- UTC
- 1988-04-19 20:48:51 UTC
- Depth
- 75.0 km (46.6 mi), intermediate-depth
- Epicenter
- 1.886° N, 127.279° E
- Region
- Indonesia
- Strongest shaking
- IV, light shaking
- Tsunami flag
- No
- Status
- Reviewed by a seismologist
Magnitude estimates
Different scales measure different things and differ by a few tenths. The USGS marks one as preferred, and it is the one this page uses.
| Mag. | Scale | Computed by | Notes |
|---|---|---|---|
| 5.9 | Mw, moment | USGS National Earthquake Information Center | Preferred · Reviewed |
| 5.84 | Mw, moment | ISC-GEM global catalog | Final · ±0.1 |
| 5.8 | Mwc, centroid moment | Global CMT project | Preliminary |
What happened
The USGS’s account of the effects of this earthquake.
Depth from broadband displacement seismograms. FAULT PLANE SOLUTION: P-Waves NP1:Strike=45 Dip=82 Slip=-90 NP2:Strike=225 Dip=8 Slip=-90 Principal Axes: (T) Plg=37 Azm=135 (P) Plg=53 Azm=315 Comment: The focal mechanism is poorly controlled and corresponds to normal faulting. The preferred fault plane is NP1. MOMENT TENSOR SOLUTION Dep 95 No. of sta: 9 Moment Tensor; Scale 10**17 Nm Mrr=-3.37 Mtt=3.65 Mff=-0.28 Mrt=-2.48 Mrf=-2.39 Mtf=1.08 Principal axes: (T) Val=5.06 Plg=21 Azm=159 (N) Val=-0.04 Plg=17 Azm=63 (P) Val=-5.02 Plg=63 Azm=297 Best Double Couple:Mo=5.0*10**17 NP1:Strike=276 Dip=28 Slip=-53 NP2:Strike=56 Dip=68 Slip=-108 CENTROID, MOMENT TENSOR (HRV) Data Used: GDSN L.P.B.: 12S, 27C Centroid Location: Origin Time 20:48:57.9 0.3 Lat 1.52N 0.04 Lon 128.00E 0.05 Dep 26.2 2.7 Half-duration 3.2 Moment Tensor; Scale 10**17 Nm Mrr=-2.88 0.20 Mtt=3.28 0.20 Mff=-0.39 0.34 Mrt=-5.71 0.84 Mrf=-1.96 0.49 Mtf=2.33 0.19 Principal Axes: (T) Val=7.79 Plg=29 Azm=157 (N) Val=-1.46 Plg=5 Azm=250 (P) Val=-6.33 Plg=60 Azm=349 Best Double Couple:Mo=7.1*10**17 NP1:Strike=231 Dip=16 Slip=-110 NP2:Strike=71 Dip=75 Slip=-84
From the USGS event page for usp0003f65. U.S. Geological Survey text and figures are in the public domain.
Shaking
The USGS ShakeMap: shaking estimated from seismic stations and the quake’s size, on the Modified Mercalli intensity scale.
- Strongest estimated
- IV, light shaking
- Peak ground acceleration
- 4.4% of gravity
- Peak ground velocity
- 0.7 cm/s
- Map
- Automatic
Did you feel it?
No one has reported feeling this quake to the USGS.
How well it is located
Reviewed by a seismologist.
- Depth from
- OPERATOR_ASSIGNED
Nearest places
Distance and direction from each place to the epicenter, with its forecast.
Nearby
Within 100 km, magnitude 2.9 and up: 4 in the 60 days after this one and 2 in the 30 days before it.
After
- 4.5Molucca Sea · 14042 days ago · 47 km deep · 61 km away
- 5.0142 km NW of Ternate, Indonesia · 14039 days ago · 73 km deep · 80 km away
- 4.782 km NNW of Tobelo, Indonesia · 13996 days ago · 33 km deep · 70 km away
- 4.6132 km W of Tobelo, Indonesia · 13988 days ago · 55 km deep · 50 km away
Before
Earthquakes todayIndonesia earthquakesLive radar here
Sources
From the USGS Earthquake Hazards Program and its partner networks, event usp0003f65 (also filed as gcmtb041988e, gcmt19880419204852, iscgem441095). Read Fri, Oct 2, 2026, 11:33 AM UTC.