September 4, 1989 Earthquake: Tembagapura, Indonesia

Name: September 4, 1989 Earthquake: Tembagapura, Indonesia
Start: 1989-09-04
Location: Tembagapura, Indonesia

September 4, 1989 · M6

A magnitude 6 earthquake struck Tembagapura, Indonesia on September 4, 1989 at 05:20:55 UTC, 9 km below the surface.

Map

Where it struck, with the other significant earthquakes within 200 km. Circles are sized and colored by magnitude; select one for its page.

The earthquake

Date: September 4, 1989
Time: 05:20:55 UTC
Place: Tembagapura, Indonesia
Magnitude: 6 (Ms)
Magnitude scales: Ms 6 · mb 5.8
Focal depth: 9 km (6 mi)
Tsunami: None recorded
Epicenter: 4.219° S, 136.667° E
Country: Indonesia
Region: Central and South Pacific
USGS record: The USGS’s page for this earthquake

Ms: surface-wave magnitude. mb: body-wave (P-wave) magnitude. NCEI’s headline magnitude is the best of these for the earthquake.

The toll

Damage: Moderate (about $1 to $5 million)

Where the literature gives no number, NCEI records a description on a scale of 1 to 4, printed here in its words. Damage is in millions of US dollars of the year of the event, not adjusted for inflation.

What happened

The USGS’s account of the effects of this earthquake.

Damage at Tembagapura. Two events about 2.5 seconds apart. Depth from broadband displacement seismograms, based on second event. FAULT PLANE SOLUTION: P-Waves NP1:Strike=123 Dip=68 Slip=90 NP2:Strike=303 Dip=22 Slip=90 Principal Axes: (T) Plg=67 Azm=33 (P) Plg=23 Azm=213 Comment: The focal mechanism is poorly controlled and corresponds to reverse faulting. The preferred fault plane is NP2. RADIATED ENERGY No. of sta: 11 Focal mech. M Energy 0.3+0.0*10**14 Nm MOMENT TENSOR SOLUTION Dep 17 No. of sta: 12 Moment Tensor; Scale 10**18 Nm Mrr=1.07 Mtt=-0.87 Mff=-0.20 Mrt=0.75 Mrf=-0.50 Mtf=0.43 Principal axes: (T) Val=1.40 Plg=70 Azm=40 (N) Val=0.00 Plg=4 Azm=299 (P) Val=-1.40 Plg=20 Azm=208 Best Double Couple:Mo=1.4*10**18 NP1:Strike=291 Dip=25 Slip=81 NP2:Strike=121 Dip=65 Slip=94 CENTROID, MOMENT TENSOR (HRV) Data Used: GDSN L.P.B.: 17S, 44C M.W.: 11S, 17C Centroid Location: Origin Time 05:21: 5.1 0.2 Lat 4.43S 0.02 Lon 136.48E 0.02 Dep 16.9 BDY Half-duration 5.1 Moment Tensor; Scale 10**18 Nm Mrr=1.75 0.03 Mtt=-1.98 0.03 Mff=0.23 0.03 Mrt=2.87 0.19 Mrf=-1.60 0.12 Mtf=0.42 0.03 Principal Axes: (T) Val=3.74 Plg=58 Azm=40 (N) Val=0.13 Plg=10 Azm=294 (P) Val=-3.87 Plg=30 Azm=199 Best Double Couple:Mo=3.8*10**18 NP1:Strike=262 Dip=17 Slip=56 NP2:Strike=117 Dip=76 Slip=100

From the USGS event page for usp0003z73. U.S. Geological Survey text and figures are in the public domain.

Magnitude estimates

The magnitudes the USGS catalog lists for this earthquake, by scale and by who computed them. NCEI’s own scales are in the table above.

Mag.	Scale	Computed by	Notes
6.4	Mw, moment	USGS National Earthquake Information Center	Preferred · Reviewed
6.33	Mw, moment	ISC-GEM global catalog	Final · ±0.1
6.3	Mwc, centroid moment	Global CMT project	Preliminary
6.0	Me, energy	Choy, USGS energy magnitude	Reviewed

Sources NCEI cites

The publications NCEI lists for this record. The numbers match the “reference #” notes in its account above.

#1053 National Earthquake Information Center (NEIC) (1971 to 2013). Preliminary Determination of Epicenters (PDE), a weekly and monthly publication, National Earthquake Information Center, U.S. Geological Survey, Golden, Colorado, 1971 to 2013.
#1232 International Seismological Centre (1964-1990). Regional Catalogue of Earthquakes, 1964-1990, Edinburgh, Scotland.

Other significant earthquakes nearby

Within 200 km, the deadliest first.

Significant earthquakes of 1989 The 1900s Every quake the USGS located in 1989 Recent earthquakes near here This day in weather history

Sources

Significant earthquakes from NOAA’s National Centers for Environmental Information, Global Historical Hazard Database, cited as NCEI/WDS, doi:10.7289/V5PN93H7. Public domain. Read 2026-10-01. NCEI earthquake 5210. The written accounts and the magnitude estimates are from the USGS earthquake catalog, event usp0003z73, matched to this record by time, place and magnitude.