M6.8 earthquake 100 km SSE of Old Harbor, Alaska
A magnitude 6.8 earthquake struck 100 km SSE of Old Harbor, Alaska on Thu, Jun 19, 1986, 1:09 AM AKDT (09:09 UTC), 17 km (10 mi) below the surface.
Map
Where this earthquake was located, with the others nearby. Select one for its page.
The earthquake
- Magnitude
- 6.8 (Mw, moment), strong
- Magnitude from
- USGS National Earthquake Information Center
- Local time
- UTC
- 1986-06-19 09:09:09 UTC
- Depth
- 16.7 km (10.4 mi), shallow
- Epicenter
- 56.331° N, 152.914° W
- Region
- Alaska
- 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 |
|---|---|---|---|
| 6.8 | Mw, moment | USGS National Earthquake Information Center | Preferred · Reviewed |
| 6.33 | Mw, moment | ISC-GEM global catalog | Final · ±0.1 |
| 6.76 | Mw, moment | USGS historic United States catalog | Final |
| 6.3 | Mwc, centroid moment | Global CMT project | Preliminary |
What happened
The USGS’s account of the effects of this earthquake.
Multiple event. First event considerably smaller. Felt (IV) at Kodiak. Depth from broadband displacement seismograms, based on larger event. FAULT PLANE SOLUTION: P-Waves NP1:Strike=33 Dip=78 Slip=90 NP2:Strike=213 Dip=12 Slip=90 Principal Axes: (T) Plg=57 Azm=303 (P) Plg=33 Azm=123 Comment: The focal mechanism is poorly controlled and corresponds to reverse faulting. The preferred fault plane is NP2. MOMENT TENSOR SOLUTION Dep 1 No. of sta: 17 Moment Tensor; Scale 10**26 d-cm Mrr=0.82 Mtt=-0.79 Mff=-0.03 Mrt=0.88 Mrf=0.99 Mtf=-0.56 Principal axes: (T) Val=1.56 Plg=60 Azm=295 (N) Val=0.15 Plg=13 Azm=48 (P) Val=-1.72 Plg=27 Azm=145 Best Double Couple:Mo=1.6*10**26 NP1:Strike=265 Dip=22 Slip=128 NP2:Strike=44 Dip=73 Slip=76 CENTROID, MOMENT TENSOR (HRV) Data Used: GDSN L.P.B.: 14S, 34C Centroid Location: Origin Time 09:09:15.5 0.3 Lat 55.93N 0.05 Lon 152.45W 0.06 Dep 15.0 FIX Half-duration 5.5 Moment Tensor; Scale 10**25 D-CM Mrr=0.75 0.05 Mtt=-0.53 0.06 Mff=-0.22 0.04 Mrt=3.26 0.11 Mrf=1.77 0.11 Mtf=-0.65 0.06 Principal Axes: (T) Val=3.69 Plg=52 Azm=335 (N) Val=0.26 Plg=3 Azm=241 (P) Val=-3.95 Plg=38 Azm=148 Best Double Couple:Mo=3.8*10**25 NP1:Strike=215 Dip=7 Slip=64 NP2:Strike=61 Dip=83 Slip=93
Maximum observed Modified Mercalli Intensity (MMI) IV
From the USGS event page for usp0002v6r. U.S. Geological Survey text and figures are in the public domain.
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 3.8 and up: 4 in the 60 days after this one and 0 in the 30 days before it.
After
Earthquakes todayAlaska earthquakesLive radar here
Sources
From the USGS Earthquake Hazards Program and its partner networks, event usp0002v6r (also filed as gcmtb061986b, ushis3956, gcmt19860619090912, iscgem493508). Read Sun, Oct 4, 2026, 4:08 PM UTC.