QuakeIndex

Earthquake · reviewed by a seismologist

M 6.8mww

210 km SW of Port McNeill, Canada

· 10 km deep · released about 240 kilotons of TNT

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Distance rings around the epicentre, with the nearest towns at their true direction and later quakes as coloured dots. Not a shaking map — see the USGS ShakeMap for that.
When
Magnitude
M 6.8 (mww)
Depth
10 km below the surface
Felt
170 reports · strongest reported intensity IV
Measured shaking
intensity IV (ShakeMap)
USGS impact alert
green
Tsunami
USGS flagged this event for tsunami evaluation. Follow tsunami.gov for official messages.
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1609 days ago

This was a strong earthquake. Damage is likely near the epicentre and it is felt over a wide area. 170 people have reported feeling it to USGS.

How big was it?

This earthquake released about 240 kilotons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 7.8 would have released about 32 times as much.

  1. San Francisco 1906 M 7.9 45× the energy of this one
  2. Ridgecrest, California 2019 M 7.1 2.8× the energy of this one
  3. Loma Prieta, California 1989 M 6.9 1.4× the energy of this one
  4. This earthquake M 6.8 about 240 kilotons of TNT
  5. Northridge, California 1994 M 6.7 this one released 1.4× more
  6. Mineral, Virginia 2011 M 5.8 this one released 32× more

Energy from the Gutenberg–Richter relation (log10E = 1.5M + 4.8), rounded to two figures; bar length is magnitude, which is already a logarithm of energy. Magnitudes of past earthquakes from the USGS catalogue.

Where

Epicentre 49.3346, -129.2890. Map © OpenStreetMap contributors.

Aftershocks so far

27 earthquakes have been recorded within 50 km since this one.

  1. 5.6 215 km SW of Port McNeill, Canada
  2. 4.4 195 km SW of Port McNeill, Canada
  3. 4.1 188 km SW of Port McNeill, Canada
  4. 4.1 193 km SW of Port McNeill, Canada
  5. 5.6 214 km SW of Port McNeill, Canada
  6. 4.1 213 km SW of Port McNeill, Canada
  7. 4.3 205 km SW of Port McNeill, Canada
  8. 6.0 237 km SW of Port McNeill, Canada
  9. 4.0 207 km SW of Port McNeill, Canada
  10. 5.0 216 km SW of Port McNeill, Canada
  11. 4.1 200 km WSW of Vernon, Canada
  12. 4.1 222 km WSW of Port McNeill, Canada
  13. 5.4 213 km WSW of Vernon, Canada
  14. 4.3 224 km SW of Port McNeill, Canada
  15. 4.9 211 km SW of Port McNeill, Canada

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of . QuakeIndex does not forecast aftershocks. When USGS issues an operational aftershock forecast it appears on the USGS event page.

For this area

The largest earthquake within 50 km in our catalogue was M 6.5 on 2018-10-22.

From the QuakeIndex catalogue, built from the USGS FDSN event service.

On USGS

QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.