John Cassidy
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earthquakeguy.bsky.social
John Cassidy
@earthquakeguy.bsky.social
5.3K followers 850 following 890 posts
NRCan earthquake seismologist + University of Victoria Adjunct Professor. Works with engineers, emergency managers, and communities to help minimize the impact of #earthquakes. Also, posts on Nature and Gardening (Zone 9a). 🌱 🧪⚒️ 🏞 🇨🇦
My thoughts/posts.
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earthquakeguy.bsky.social
The most wonderful time of the year...
fresh-picked #lemons from our backyard Meyer lemon tree on southern Vancouver Island.
Soon - Italian lemon bars, lemon meringue pie, lemonade and more. Ideas welcome.
🌱🇨🇦
Photo of bright yellow, large, fresh-picked lemons from our in-ground tree on southern Vancouver Island. Photo of our backyard, in-ground lemon tree with both yellow lemons ready to pick and green lemons for next spring.
November 22, 2025 at 6:17 PM
earthquakeguy.bsky.social
The November 20, 1933 M7.3 #earthquake offshore Baffin Island, #Nunavut triggered submarine landslides.
See some of the latest research here:
cdnsciencepub.com/doi/full/10....
🧪⚒️🌊
November 20, 2025 at 9:25 PM
earthquakeguy.bsky.social
Nov. 20, 1933: A M7.3 earthquake struck offshore Baffin Island, #Canada. This is the largest known #earthquake along the passive margin (east/north coasts) of #NorthAmerica and north of the Arctic Circle. This remains a seismically active area:
www.earthquakescanada.nrcan.gc.ca/historic-his...
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Map showing the location of the November 20, 1933 M7.3 earthquake offshore Baffin Island.
November 20, 2025 at 4:05 PM
earthquakeguy.bsky.social
If you live in the #PacificNorthwest or southern #BritishColumbia, this is good to know!
⚒️🧪🌋
pnsn1.bsky.social Pacific Northwest Seismic Network @pnsn1.bsky.social · 4d
Some false reports are circulating that Mt. Rainier is suddenly showing seismic tremor activity — this is not true. The signal being referenced is actually radio interference, most likely due to rime ice buildup on the antenna of one of our seismic stations.
November 19, 2025 at 6:51 PM
earthquakeguy.bsky.social
Large earthquakes off the east coast 🇨🇦? Yes.
Nov. 18, 1929: a M7.2 #earthquake struck south of #Newfoundland. Strong shaking + damage on Cape Breton Island. Felt as far away as Montreal, Ottawa + #NewYorkCity.
It also triggered a large #tsunami.
www.earthquakescanada.nrcan.gc.ca/historic-his...
⚒️🧪
Map showing the location of the November 18, 1929 offshore Newfoundland earthquake and the strength of ground shaking. Shaking was felt across the maritime provinces and as far away as Ottawa and New York City.
November 18, 2025 at 4:43 PM
earthquakeguy.bsky.social
Thanks to everyone who provided advice on the #tomato plants!
Mid-November update - we are still getting tomatoes! Not nearly as many, but as long as they are pinkish, they ripen inside quickly. No frost in the forecast, so perhaps we won't have to buy tomatoes until December?
🌱🇨🇦
#VancouverIsland
Photo of fresh (mid-November) Juliet tomatoes from the garden. Some red, some pinkish and some mostly green to see if they ripen. Green grass and some yellow leaves in the background.
November 15, 2025 at 7:04 PM
earthquakeguy.bsky.social
#RemembranceDay
So grateful to all of the women and men who serve or have served to protect #Canada.
Remembering my Dad and all of my uncles who served in the Royal Canadian Navy. These photos are from the 2020 Royal Canadian Navy Victoria shoreline sail past.
#CanadaRemembers #LestWeForget 🇨🇦
Photo of a Royal Canadian naval vessel sailing past Victoria. Grey skies and a grey sea. Mountains in the distant background. Daughter and grandson on the beach watching the Royal Canadian Navy sailpast of Victoria in 2020. Grey skies, grey seas, and a colourful red jacket.
November 11, 2025 at 4:54 PM
earthquakeguy.bsky.social
The huge footprint of large earthquakes…
The 3 November, 2002 M7.9 Denali #earthquake had impacts to distances of 3500+ km across western Canada. Shaking caused people to feel seasick, chandeliers swayed, water wells turned muddy and seiches were generated
pubs.geoscienceworld.org/ssa/bssa/art...
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Four maps of western Canada showing unusual effects of the 2002 Denali earthquake. Shaking was felt to 3500 km distance, people felt seasick/dizzy, chandeliers swayed, water wells turned muddy and seiches were generated.
November 3, 2025 at 3:04 PM
earthquakeguy.bsky.social
A question for my gardening friends...
Should it stay, or should it go now?
This Juliet tomato plant still has lots of cherry tomatoes. The November sun is not very strong, so they turn pink slowly. No frost for
the forseeable future, about 13C /55F highs and about 7C /45F lows.
Thanks for advice 🌱
Juliet tomato plant with green leaves and mostly green or pinkish tomatoes in November.
November 2, 2025 at 9:25 PM
earthquakeguy.bsky.social
Large earthquakes in eastern #Canada?
Yes.
November 1, 1935: a damaging M6.1 quake struck Témiscaming, #Québec. Chimneys collapsed, landslides were triggered. Felt across #Ontario, QC, NB and from Chicago to #NYC to Virginia. Details:
earthquakescanada.nrcan.gc.ca/historic-his...
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Map showing how the November 1, 1935 M6.1 Témiscaming, #Québec was felt across eastern North America. Shaking was felt across ON, QC, NB and from Chicago to New York City to Virginia.
November 2, 2025 at 4:57 PM
earthquakeguy.bsky.social
Welcome to November! The red banana plants are still happy (despite the recent monsoon) and the Mexican Orange plant is getting it's second, smaller bloom. Fall is in the air though...
#VancouverIsland
🌱🇨🇦
Red banana plant in the garden. Still relatively happy, even though it is November. A second bloom of white and yellow blossoms on the Mexican Orange plant. Green leaves and blue skies in the background.
November 1, 2025 at 9:19 PM
earthquakeguy.bsky.social
View from the office, October 30th update. Not too bad...
#yyj
#VancouverIsland
🌱📷🇨🇦
Photo taken on October 30 showing red fall colours on the Maple trees. with blue sky behind.
October 30, 2025 at 11:19 PM
earthquakeguy.bsky.social
Fish in the forest, seaweed in trees?
Yes - 13 years ago tonight, the M7.8 #HaidaGwaii earthquake generated the world's largest #tsunami of 2012. Runup to 13m in some inlets left seaweed in trees and fish in the forest. If you are near water and feel long and strong shaking, go to high ground.
🧪🌊⚒️
A photo of seaweed in trees and a GPS unit to measure the height above sea level. The seaweed in the trees was deposited by the October 27th, 2012 tsunami generated by an offshore M7.8 earthquake. GSC photo.
October 27, 2025 at 10:51 PM
earthquakeguy.bsky.social
13 years ago today (at 8:04 pm) a M7.8 earthquake rocked #HaidaGwaii. This offshore #earthquake was felt to more than 1000 km distance, caused strong shaking, landslides, a tsunami and was followed by 1000's of aftershocks
link.springer.com/article/10.1...
pubs.geoscienceworld.org/bssa/issue/1...
⚒️🧪
A map of Haida Gwaii showing the location of the 2012 M7.8 earthquake and aftershocks. A map of British Columbia showing where and how ground shaking from the 2012 M7.8 earthquake was felt. Shaking ranged from very strong on Haida Gwaii to weak shaking on Vancouver Island.
October 27, 2025 at 1:59 PM
earthquakeguy.bsky.social
Well, this could be some of the last tomatoes, beans, and cucumbers of the season,
but - beets, squash, lettuce, arugula, and Swiss chard are going strong (and fresh lemons also).
🌱🇨🇦
Photo of freshly picked yellow and green beans, cucumbers, and tomatoes. some of the last of the season on Vancouver Island. Photo of a raised garden bed in late October with green onions, arugula, lettuce, Swiss chard and squash plants growing. There is a deer fence in the background. Photo of an in ground lemon tree on Vancouver Island with many lemons ready to pick.
October 25, 2025 at 5:05 PM
earthquakeguy.bsky.social
Did you feel shaking on southern #VancouverIsland at 05:30 PDT this morning? That was a M3.1 #earthquake beneath Salt Spring Island, about 13 km N of #Sidney and 13 km SE of #Ganges. Felt across the region. For details and to report shaking:
www.earthquakescanada.nrcan.gc.ca/recent/2025/...
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Seismograms showing ground shaking from the October 21 M3.1 earthquake beneath Salt Spring Island at 5:30 a.m. Map showing the location of today's M3.1 earthquake beneath Salt Spring Island, 13 km southeast of Ganges and 13 km north of Sidney.
October 21, 2025 at 1:50 PM
earthquakeguy.bsky.social
When #seismology meets #meteorology!
Ground shaking across #VancouverIsland is ramping up (but not felt) as the remnants of Tyhpoon Nakri approach the west coast.
The ground shaking started increasing just after midnight Pacific time (07:00 UTC on this figure) Oct. 17, as the storm gets closer.
⚒️🧪🌀🇨🇦
A plot of ground shaking on southern Vancouver Island over the past 24 hours (thanks to the IRIS Consortium: https://www.iris.edu/app/station_monitor/ Stronger ground shaking (not felt) is observed starting just after midnight (Pacific time) or 07:00 UTC as used on this plot, as the storm gets closer.
October 17, 2025 at 9:22 PM
earthquakeguy.bsky.social
Right on schedule! More than 10,000 tiny tremors (not felt) have rolled through #PugetSound and southern #VancouverIsland over the past 30 days. This is Episodic Tremor and Slip (ETS) and occurs here every 12-16 months:
www.earthquakescanada.nrcan.gc.ca/pprs-pprp/pu...
Also - it is #ShakeOut day!
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Map of the Puget Sound and Vancouver Island region showing the location of tiny ETS tremors (not earthquakes and not felt) from September 15 - October 15. Locations are colour-coded by time.
October 16, 2025 at 2:25 PM
earthquakeguy.bsky.social
Are you ready for the #ShakeOut drill tomorrow (10:16 a.m. Oct. 16th)?
Do you want to learn more about #earthquakes and #tsunamis?
Bring your questions and join us this evening at 7 p.m. PT for our free Webinar and Q+A session.
Register:
us02web.zoom.us/webinar/regi...
@shakeoutbc.bsky.social
⚒️🧪🇨🇦
Image of a poster highlighting this evening's Earthquake Webinar and question and answer session as a part of ShakeOut week.
October 15, 2025 at 10:37 PM
earthquakeguy.bsky.social
Not a bad view from the office today...
🧪⚒️🇨🇦
#VancouverIsland
#yyj
View of maple trees with beautiful red leaves set against the blue sky. The blue waters of Patricia Bay are visible, with the hills of Salt Spring Island in the distance.
October 14, 2025 at 6:19 PM
earthquakeguy.bsky.social
Some mid-October beach therapy.
southern #VancouverIsland.
#Victoria
#beach
🇨🇦 📷
October 13, 2025 at 10:56 PM
earthquakeguy.bsky.social
Oh Winston, our hearts are broken. We are so grateful for the 15+ years that you spent with us. Thank you for the many (many!) 1000's of walks and hikes. Thank you for always being there and for always watching out the window for our return, then greeting us at the door. Miss you forever
#Dogs
#Love
Photo of a young Winston, our black, white and tan English setter, sitting out on the deck. Green grass in the background. Photo of Winston, at about 5 years of age, relaxing on a lounge chair on the deck, soaking up the sun. A close-up photo of Winston lying on the carpet, relaxing. Photo of a 15+ year-old Winston sitting on his brown chair in the window watching for our return.
October 8, 2025 at 2:44 PM
earthquakeguy.bsky.social
It is nice to see the tall, pampas grass plumes return. They are beautiful - until the rains begin in November! Enjoy while they are here...
🌱📷
Photo of tall, white plumes of pampas grass. Green leaves below, and a tall green cedar tree behind.
October 4, 2025 at 7:30 PM
earthquakeguy.bsky.social
September may be winding down, but my #VancouverIsland garden sure isn't! Just picked - green beans, yellow beans, cucumbers, beets, snap peas, cucamelons, apples, lemons and tomatoes... so many tomatoes! Lots of kale, spinach, arugula and lettuce planted for the Fall and Winter. 🌱🇨🇦
Photo of fresh-picked tomatoes, beets, yellow and green beans, cucumbers, apples, lemon, snap peas and cucamelons ( that look like tiny watermelons).
September 28, 2025 at 10:34 PM
earthquakeguy.bsky.social
On #VancouverIsland you don't have to go far to find trees that are perfect for #ThickTrunkTuesday
This is a large Douglas Fir in #Victoria. 🌱📸🌲
#Photography
#Trees
#Canada
Photo of a large Douglas Fir tree on southern Vancouver Island.
September 23, 2025 at 1:50 PM