Harold Tobin
@haroldtobin.bsky.social
UW prof and director of the Pacific Northwest Seismic Network. WA State Seismologist. All about subduction zones and very messed up rocks.
This visualization of Japan’s M6.8 yesterday is phenomenal. Offshore S-net detected it and issued earthquake alert before any land station detection. Numbered circles show JMA intensity (not same as MMI). Offshore is where we need to be in Cascadia as well.
The underwater seismometer network is so great, as evidenced from yesterday's EQ off-Tohoku.
Reposting unofficial visualization by x.com/kotoho76/sta...
Reposting unofficial visualization by x.com/kotoho76/sta...
November 10, 2025 at 4:10 PM
This visualization of Japan’s M6.8 yesterday is phenomenal. Offshore S-net detected it and issued earthquake alert before any land station detection. Numbered circles show JMA intensity (not same as MMI). Offshore is where we need to be in Cascadia as well.
Today's Japan M6.8 is in an interesting spot: the zone of "missing" slip just north of the very large shallow rupture in the 2011 M9.
⚒️ 🧪
A M6.8 earthquake struck offshore Japan today - another large earthquake from the subduction zone that produced two recent great earthquakes. The earthquake was preceded by a "cascade up": foreshocks progressively increasing in maximum magnitude.
What do we know? What might happen next?
A M6.8 earthquake struck offshore Japan today - another large earthquake from the subduction zone that produced two recent great earthquakes. The earthquake was preceded by a "cascade up": foreshocks progressively increasing in maximum magnitude.
What do we know? What might happen next?
M6.8 earthquake offshore Japan preceded by upward cascade of foreshocks
What do we know about seismic hazard in the Japan-Kuril subduction zone?
earthquakeinsights.substack.com
November 9, 2025 at 7:36 PM
Today's Japan M6.8 is in an interesting spot: the zone of "missing" slip just north of the very large shallow rupture in the 2011 M9.
Quoted supporting our counterparts and friends at the Alaska Earthquake Center. The cost of the U.S. tsunami warning and mitigation effort is really a pittance. None of it has ever been adequately funded in any administration, and now things are worse. ⚒️ www.nbcnews.com/science/tsun...
U.S. tsunami warning system, reeling from funding and staffing cuts, is dealt another blow
Seismic monitoring stations in Alaska are closing after a denied federal grant, risking delayed tsunami warnings for people living on the West Coast.
www.nbcnews.com
November 9, 2025 at 7:03 PM
Quoted supporting our counterparts and friends at the Alaska Earthquake Center. The cost of the U.S. tsunami warning and mitigation effort is really a pittance. None of it has ever been adequately funded in any administration, and now things are worse. ⚒️ www.nbcnews.com/science/tsun...
Reposted by Harold Tobin
Geno Suarez hits a Grand Slam to put the Mariners up 6-2 and seal Game 5 of the ALCS!
"The City is Shaking!"
#SeizeTheMoment
"The City is Shaking!"
#SeizeTheMoment
October 18, 2025 at 1:25 AM
Geno Suarez hits a Grand Slam to put the Mariners up 6-2 and seal Game 5 of the ALCS!
"The City is Shaking!"
#SeizeTheMoment
"The City is Shaking!"
#SeizeTheMoment
Reposted by Harold Tobin
You feel that Seattle?! Check out that Polanco P-Wave! Polanco Game Winning Single, Crawford Scores, MARINERS WIN!! @Mariners are Toronto Bound! @Tmobilepark @FoxSports
#SeisTheMoment #SeizeTheMoment
#SeisTheMoment #SeizeTheMoment
October 11, 2025 at 5:20 AM
You feel that Seattle?! Check out that Polanco P-Wave! Polanco Game Winning Single, Crawford Scores, MARINERS WIN!! @Mariners are Toronto Bound! @Tmobilepark @FoxSports
#SeisTheMoment #SeizeTheMoment
#SeisTheMoment #SeizeTheMoment
Reposted by Harold Tobin
Dubs is ready to #ShakeOut... Are you?
We’re just ONE WEEK away from the Great ShakeOut earthquake drill on October 16! Join Dubs in practicing Drop, Cover, and Hold On.
Register your participation and explore all the ways you can boost awareness for this event at shakeout.org.
We’re just ONE WEEK away from the Great ShakeOut earthquake drill on October 16! Join Dubs in practicing Drop, Cover, and Hold On.
Register your participation and explore all the ways you can boost awareness for this event at shakeout.org.
October 10, 2025 at 12:00 AM
Dubs is ready to #ShakeOut... Are you?
We’re just ONE WEEK away from the Great ShakeOut earthquake drill on October 16! Join Dubs in practicing Drop, Cover, and Hold On.
Register your participation and explore all the ways you can boost awareness for this event at shakeout.org.
We’re just ONE WEEK away from the Great ShakeOut earthquake drill on October 16! Join Dubs in practicing Drop, Cover, and Hold On.
Register your participation and explore all the ways you can boost awareness for this event at shakeout.org.
Interesting study! And this animation blending the model with the observed SWOT image is gorgeous.
On July 29, 2025 a Mw 8.8 earthquake off Kamchatka launched a Pacific-wide tsunami, right as the SWOT satellite flew south-to-north taking altimetry measurements of the wave train. In our new preprint, we pair SWOT with nearby DART buoys to capture the tsunami’s propagation and its source
October 1, 2025 at 6:31 PM
Interesting study! And this animation blending the model with the observed SWOT image is gorgeous.
Tsunami evacuation systems in Kochi City and Kure town, Shikoku Island. The 1946 Nankai Trough earthquake and tsunami swept ashore here, flooding all these areas - only the most recent of many over the past ~1300 years. The vertical evac towers are really impressive.
September 28, 2025 at 7:13 PM
Tsunami evacuation systems in Kochi City and Kure town, Shikoku Island. The 1946 Nankai Trough earthquake and tsunami swept ashore here, flooding all these areas - only the most recent of many over the past ~1300 years. The vertical evac towers are really impressive.
Yokonami melange, a paleo-megathrust, and so, so much chert, near Kure, Shikoku Island, Japan
September 28, 2025 at 7:01 PM
Yokonami melange, a paleo-megathrust, and so, so much chert, near Kure, Shikoku Island, Japan
We recently spent 2 weeks doing field work in a remote part of Olympic National Park, studying what we think is another part of the 'fossil' subduction plate boundary fault: a paleo-megathrust. The terrain was rugged and challenging, and the rocks were rewarding. Here's a taste. ⚒️
September 12, 2025 at 5:30 AM
We recently spent 2 weeks doing field work in a remote part of Olympic National Park, studying what we think is another part of the 'fossil' subduction plate boundary fault: a paleo-megathrust. The terrain was rugged and challenging, and the rocks were rewarding. Here's a taste. ⚒️
And Steve Malone is still analyzing volcanic earthquakes at PNSN in 2025!
#MSH45 | Aug. 7, 1980 — Eruption #5
On the University of Washington campus, seismologists Steve Malone and Craig Weaver are hosting a documentary crew when harmonic tremors hit Mount St. Helens early afternoon.
Phones, charts, decisions—fast. Hours later, St. Helens delivers.
@pnsn1.bsky.social
On the University of Washington campus, seismologists Steve Malone and Craig Weaver are hosting a documentary crew when harmonic tremors hit Mount St. Helens early afternoon.
Phones, charts, decisions—fast. Hours later, St. Helens delivers.
@pnsn1.bsky.social
August 15, 2025 at 5:01 AM
And Steve Malone is still analyzing volcanic earthquakes at PNSN in 2025!
This eruption is an interesting … coincidence?? Seismically triggered eruptions are not really my specialty, but I answered the phone on Sunday morning when @npr.org’s @gbrumfiel.bsky.social called, so here you go: Russian volcano erupts days after monster quake shakes
www.npr.org/2025/08/03/n...
www.npr.org/2025/08/03/n...
Russian volcano erupts days after monster quake shakes region
The volcano may have been primed to erupt before the magnitude 8.8 quake pushed it over the edge.
www.npr.org
August 4, 2025 at 3:58 AM
This eruption is an interesting … coincidence?? Seismically triggered eruptions are not really my specialty, but I answered the phone on Sunday morning when @npr.org’s @gbrumfiel.bsky.social called, so here you go: Russian volcano erupts days after monster quake shakes
www.npr.org/2025/08/03/n...
www.npr.org/2025/08/03/n...
Here is @noaa.gov's model of the tsunami propagation from the people at PMEL, initiated with the earthquake location and then calibrated by the DART buoy observations. There is a wealth of great information at their website (link in thread). (1/6) ⚒️ www.youtube.com/watch?v=oOtJ...
Kamchatka Tsunami, July 29, 2025 tsunami propagation
YouTube video by NOAAPMEL
www.youtube.com
August 2, 2025 at 5:15 PM
Here is @noaa.gov's model of the tsunami propagation from the people at PMEL, initiated with the earthquake location and then calibrated by the DART buoy observations. There is a wealth of great information at their website (link in thread). (1/6) ⚒️ www.youtube.com/watch?v=oOtJ...
Went on CBS Mornings today to talk about the tsunami and how it all unfolded. They had good questions. www.cbsnews.com/video/why-a-...
Why a recent earthquake didn't wreak havoc, despite its power
After an 8.8 magnitude earthquake off Russia's coast triggered tsunami alerts as far as the U.S., experts like seismologist Harold Tobin explain why the impact was far less devastating than expected.
www.cbsnews.com
August 1, 2025 at 10:13 PM
Went on CBS Mornings today to talk about the tsunami and how it all unfolded. They had good questions. www.cbsnews.com/video/why-a-...
The M8.8 off Kamchatka appears to be the largest earthquake ever recorded that apparently didn't kill anyone. That's really remarkable, if true. ⚒️
July 31, 2025 at 5:16 PM
The M8.8 off Kamchatka appears to be the largest earthquake ever recorded that apparently didn't kill anyone. That's really remarkable, if true. ⚒️
I am glad @evanbush.bsky.social used this quote in this excellent @nbcnews.com story. This is a key message I really wanted to get across in interviews today. Article here: www.nbcnews.com/science/scie...
July 31, 2025 at 3:02 AM
I am glad @evanbush.bsky.social used this quote in this excellent @nbcnews.com story. This is a key message I really wanted to get across in interviews today. Article here: www.nbcnews.com/science/scie...
Wednesday evening, tsunami waves are still sloshing around at Port Angeles, WA ... 18+ hours after they first arrived. Source: @noaa.gov tide gauge website. ⚒️
July 31, 2025 at 2:58 AM
Wednesday evening, tsunami waves are still sloshing around at Port Angeles, WA ... 18+ hours after they first arrived. Source: @noaa.gov tide gauge website. ⚒️
Reposted by Harold Tobin
NEW: A magnitude 8.8 megaquake blasted tsunami waves across the Pacific today. Here's everything you need to know about it, including:
-Why it happened
-Why it generated a widespread tsunami
-Why the timing of this megaquake is a bit weird
Me, for NatGeo www.nationalgeographic.com/science/arti...
-Why it happened
-Why it generated a widespread tsunami
-Why the timing of this megaquake is a bit weird
Me, for NatGeo www.nationalgeographic.com/science/arti...
What caused the 8.8 magnitude quake that sent tsunamis to Hawaii and California
Here's what we know about what caused the earthquake off Russia's Far East and why the tsunami it generated weren't as big as anticipated.
www.nationalgeographic.com
July 30, 2025 at 3:34 PM
NEW: A magnitude 8.8 megaquake blasted tsunami waves across the Pacific today. Here's everything you need to know about it, including:
-Why it happened
-Why it generated a widespread tsunami
-Why the timing of this megaquake is a bit weird
Me, for NatGeo www.nationalgeographic.com/science/arti...
-Why it happened
-Why it generated a widespread tsunami
-Why the timing of this megaquake is a bit weird
Me, for NatGeo www.nationalgeographic.com/science/arti...
Reposted by Harold Tobin
Another earthquake story from @sciam.bsky.social by the always-excellent @squigglyvolcano.bsky.social explaining why the tsunami from the Russia quake wasn't as huge as the one from the 2011 Japan quake, for example. 🧪
Why the Russia Earthquake Didn't Cause a Huge Tsunami
Russia's magnitude-8.8 earthquake spawned serious tsunami warnings, but waves have been moderate so far. Here's the geological reason why
www.scientificamerican.com
July 30, 2025 at 4:07 PM
Another earthquake story from @sciam.bsky.social by the always-excellent @squigglyvolcano.bsky.social explaining why the tsunami from the Russia quake wasn't as huge as the one from the 2011 Japan quake, for example. 🧪
Today's M8.8 (orange circle) and the 1952 M9.0 epicentral locations, separated by only 73 years. I wouldn't have thought that possible! Average recurrence intervals don't tell the full story. ⚒️
July 30, 2025 at 4:35 AM
Today's M8.8 (orange circle) and the 1952 M9.0 epicentral locations, separated by only 73 years. I wouldn't have thought that possible! Average recurrence intervals don't tell the full story. ⚒️
This is a VERY large earthquake, possibly/probably among the 10 largest ever recorded. A clear subduction zone megathrust event. And it is another M>8.5 event with a notable foreshock (the recent M7.4 in same location), like Tohoku in 2011.
July 30, 2025 at 12:36 AM
This is a VERY large earthquake, possibly/probably among the 10 largest ever recorded. A clear subduction zone megathrust event. And it is another M>8.5 event with a notable foreshock (the recent M7.4 in same location), like Tohoku in 2011.
I'm excited to announce that we are seeking an External Engagement Lead for the Pacific Northwest Seismic Network! PNSN is the trusted authority on earthquakes and related topics in the PNW. Help us shape earthquake preparedness, advocacy for resilience, and hazards information all across Cascadia.
Position opening at the Pacific Northwest Seismic Network. For more information and to apply please visit bit.ly/4lHmP8M
July 14, 2025 at 8:59 PM
I'm excited to announce that we are seeking an External Engagement Lead for the Pacific Northwest Seismic Network! PNSN is the trusted authority on earthquakes and related topics in the PNW. Help us shape earthquake preparedness, advocacy for resilience, and hazards information all across Cascadia.
The 2025 earthquake swarm is now the largest one ever recorded at Mt. Rainier. It exceeds even the 2009 swarm in cumulative magnitude and event number and rate. >340 quakes located by @pnsn1.bsky.social so far, with 1000s more detected. Still not showing signs of unrest. www.usgs.gov/observatorie...
Monitoring stations detect small magnitude earthquakes at Mount Rainier
An earthquake swarm that started at Mount Rainier on July 8, 2025, is the most significant seismicity at the volcano since 2009.
www.usgs.gov
July 10, 2025 at 7:00 PM
The 2025 earthquake swarm is now the largest one ever recorded at Mt. Rainier. It exceeds even the 2009 swarm in cumulative magnitude and event number and rate. >340 quakes located by @pnsn1.bsky.social so far, with 1000s more detected. Still not showing signs of unrest. www.usgs.gov/observatorie...
Here is a good non-technical article explaining what is going on at Mt. Rainier today. Biggest swarm since 2009; not rising to the level of "unrest" and not concerning at this point. But very interesting and a sign that Rainier is absolutely an active volcano! ⚒️ www.seattletimes.com/seattle-news...
Stay calm. The ‘earthquake swarm’ at Mount Rainier is normal
Hundreds of earthquakes are detected at or near Mount Rainier each year, though typical swarms are smaller than what started last night.
www.seattletimes.com
July 8, 2025 at 11:36 PM
Here is a good non-technical article explaining what is going on at Mt. Rainier today. Biggest swarm since 2009; not rising to the level of "unrest" and not concerning at this point. But very interesting and a sign that Rainier is absolutely an active volcano! ⚒️ www.seattletimes.com/seattle-news...