Mw 7.1 offshr SE Mindanao, Philippines

[davenn]

Mw 7.1 offshore SE Mindanao, Philippines, this morning

M 7.1 - 63 km E of Pondaguitan, Philippines
2021-08-11 17:46:14 (UTC)
6.455°N 126.742°E
65.6 km depth

from my seismo

 

[berkeman]

Looks like no significant damage and no Tsunami warning, thank goodness.

https://www.reuters.com/world/asia-...strikes-mindanao-philippines-emsc-2021-08-11/

 

[davenn]

Tsunami warning, thank goodness.

Yes, fortunately. Would be unusual for a M7.1 to generate a tsunami, but it does happen.
It's usually because of a secondary effect of the quake ... above or undersea landslide or similar

Dave

 

[Astronuc]

Would be unusual for a M7.1 to generate a tsunami, but it does happen.

Under the right conditions, including depth and location. For example,
2018 Sulawesi earthquake and tsunami
https://en.wikipedia.org/wiki/2018_Sulawesi_earthquake_and_tsunami

The magnitude 7.5 quake (depth 39.0 km (24.2 mi)) was located 70 km (43 mi) away from the provincial capital Palu and was felt as far away as Samarinda on East Kalimantan and also in Tawau, Malaysia.

Now that was 7.5, which is much stronger the 7 - 7.1 Mag. In addition, the earthquake in the OP has a depth 65.6 km.

https://www.usgs.gov/faqs/what-it-about-earthquake-causes-a-tsunami

 

[davenn]

Under the right conditions, including depth and location. For example,
2018 Sulawesi earthquake and tsunami

Yes, one the ones I had in mind

another one, that I always think of, was the ...
"On July 17, 1998, a 7.0 magnitude (Mw) earthquake struck the island of Papua New Guinea at 5:49 p.m. local time. But the terror for the villagers on the islands was far from over after the ground stopped shaking. Three catastrophic tsunami waves followed—devastating and razing the entire villages of Sissano, Warapu, Arop, and Malomo on the north coast of Papua New Guinea, killing at least 1,600 people, injuring 1,000, and displacing more than 10,000 people"

I remember this one well as we discussed it when I was at university geology dept.
Because for a while the real source of the tsunami wasnt found.

"The tsunami in Papua New Guinea had confirmed run-up heights of 15 meters (49 feet) at the village of Arop and 10–15 meters (33-49 feet) on a 25-kilometer (15-mile) stretch of coastline from the village of Sissano to Teles.
While most tsunamis are triggered by earthquakes, the tsunami that devastated Papua New Guinea was quite different. Since it arrived ten minutes later than predicted from earthquake sources, scientists determined that a submarine landslide generated by the earthquake actually triggered the tsunami.

This unusual occurrence generated interest in tsunami hazards in many parts of the world not previously considered at high risk of earthquake-generated landslide tsunamis. This event also brought to light the need for every country to identify the scope of their tsunami probability hazard and develop a tsunami preparedness plan."

https://www.ncei.noaa.gov/news/day-papua-new-guinea-tsunami-1998Dave

 

[Astronuc]

"On July 17, 1998, a 7.0 magnitude (Mw) earthquake struck the island of Papua New Guinea at 5:49 p.m. local time.

https://www.usgs.gov/centers/pcmsc/...ce_center_objects=0#qt-science_center_objects

USGS image has depth of 6 km. And they corrected the magnitude to 7.6.
https://earthquake.usgs.gov/earthquakes/eventpage/usp000bbpf/executive

Shallow and near the coast would be a concern for tsunamis.For those interested - Tectonic summaries of magnitude 7 and greater earthquakes from 2000 to 2015 https://pubs.er.usgs.gov/publication/ofr20161192