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Lucy Jones @drlucyjones.bsky.social · Sep 2

This was a fun interview. It ended up being quite a retrospective on how seismology has changed over the 4 decades I have been in Pasadena. making-l-a.simplecast.com/episodes/luc...

Lucy Jones: Seismology, ShakeOuts, and String Quartets | Making Los Angeles

What do Chinese literature, medieval string instruments, and earthquake drills have in common? In Los Angeles, the answer is Lucy Jones. Often called “L.A.’s earthquake queen” — a nickname she’s not e...

making-l-a.simplecast.com

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Lucy Jones @drlucyjones.bsky.social · Aug 6

Only the Rialto events are aftershocks to the July 31 M4.3. The Lytle Creek events are near the San Andreas but not necessarily on it. We often see small events around the San Andreas but some analyses suggest they are on small faults not the main surface that will move in the big quakes.

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Lucy Jones @drlucyjones.bsky.social · Aug 6

In the last 24 hours, we have seen several M3s in 3 locations. The events near Ontario are at the western end of the Fontana trend. The Lytle Creek events are near the San Andreas & the Rialto events are where the Fontana trend intersects the San Andreas. Last week's M4.3 was at the Rialto location

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Lucy Jones @drlucyjones.bsky.social · Aug 3

The New York - Philadelphia - Wilmington urban corridor has felt small earthquakes roughly every 2-3 years. Moderately damaging earthquakes strike somewhere in the urban corridor roughly twice a century. So infrequent but not weird

Dr. Wendy Bohon @drwendyrocks.bsky.social · Aug 3

M 3.0 - NE of Hasbrouck Heights, New Jersey

Did you feel it? Report it!

earthquake.usgs.gov/earthquakes/...

Location of the earthquake is marked with a star

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Lucy Jones @drlucyjones.bsky.social · Jul 31

On the M4.3 on the Fontana trend

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Lucy Jones @drlucyjones.bsky.social · Jul 31

Looks like a small swarm in the Fontana trend. This M4.2 had a few foreshcoks including a M3.0. The Fontana trend is a NE-striking lineation of earthquakes under the sediments of the San Bernardino Vslley. We believe it is one of the left-lateral striking faults that are south of the San Gabriels.

Caltech Quake Bot @caltechquake.bsky.social · Jul 31

#AutoEQ A magnitude 4.2 (MI) #earthquake has occurred 4 mi W of Muscoy, CA at 09:32 PDT Jul 31, 2025 [2025-07-31 16:32 UTC]. #SCSN has not yet confirmed this event. For more info visit http://earthquake.usgs.gov/earthquakes/eventpage/ci41249496#executive

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Lucy Jones @drlucyjones.bsky.social · Jul 30

I’m seeing lots of questions about whether the rate of great earthquakes is changing or whether climate change affects earthquakes. The answer is no. The long term rate of these big events is about 1/decade. But the distribution is random. The last one was 2011 in Japan

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Lucy Jones @drlucyjones.bsky.social · Jul 30

The 7/29/2025 M8.8 looks like a repeat of an earthquake in 1952

Jascha Polet @jascha.bsky.social · Jul 30

Another quick comparison of the 1952 #Kamchatka #earthquake from MacInnes et al. (2010) with today’s M8.8 event. The aftershock areas are similar, as well as one region of foreshocks. The updated USGS rupture model has a max slip of 10m versus 12m for 1952, with SW rupture direction. 🧪⚒️

Figure from Macinnes et al. conpared to map of today’s Kamchatka earthquake by Jascha Polet.

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Reposted by Lucy Jones

Dr. Wendy Bohon @drwendyrocks.bsky.social · Jul 16

In addition to many M7+ earthquakes, this boundary has also hosted half a dozen M8+ earthquakes. Red circles mark the epicenter above the site where fault rupture began, and yellow shows the area on the megathrust fault that ruptured.

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Lucy Jones @drlucyjones.bsky.social · Jul 16

Not obviously. Quakes are many kms below the surface so surface impacts rarely make a difference. Water table depletion can reduce the pore pressures (pressure in the water at depth) and that can slightly reduce the risk (just like fracking-related injection increases the pressure causing quakes)

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Lucy Jones @drlucyjones.bsky.social · Jul 12

This is normal behavior. We expect most M4.3's to have some aftershocks. Quakes in the Imperial Valley tend to have more aftershocks than other places.

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Lucy Jones @drlucyjones.bsky.social · Jun 24

I once had a M2.7 directly under my house that felt so strong I went to work without waiting for a page (in pre-Internet days). It's a good reminder that how strong the shaking feels has much more to do with how close you are to the event. Duration of shaking is better for guessing magnitude.

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Lucy Jones @drlucyjones.bsky.social · Jun 24

Even very small quakes can be felt if you are nearby (and a shallow quake is closer to people on the surface). But there is not much to be said about an M2.7 except that it happened
earthquake.usgs.gov/earthquakes/...

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Reposted by Lucy Jones

Jón Frímann @jonfr500.bsky.social · Jun 17

Most births in Iceland are in the summer.

www.youtube.com/shorts/oRw8d...

Icelandic Independence Day #nordic #comedy #denmark #iceland #history #language

YouTube video by Ólafur Waage

www.youtube.com

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Lucy Jones @drlucyjones.bsky.social · Jun 10

In Dante’s Peak, the volcanologist has to choose between his first chance for sex in 5 years or tracking down a geochemical anomaly and he goes after the anomaly. That’s as realistic as it gets

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Lucy Jones @drlucyjones.bsky.social · Jun 10

Both 1974 Earthquake & Dante’s Peak are realistic about the scientists. In Earthquake, the Lab director talking to the Mayor - we are seeing something unusual but we don’t know what it means - felt like our experience after Landers, worried that it might trigger the San Andreas

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Lucy Jones @drlucyjones.bsky.social · Jun 8

This study uses "overdue" to mean that time time since the last quake is longer than the average time between earthquakes. But that doesn't mean the next quake is more likely in the near future. The length of intervals between events is very variable even at one location.

Maria McKenna @craicinsf.bsky.social · Jun 7

Can you expand on what you mean?

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Lucy Jones @drlucyjones.bsky.social · Jun 7

This does not mean the big earthquake is more likely. Whatever is making for long intervals is happening now.

A Better Bay Area @sustainablebayarea.bsky.social · Jun 7

Study says California is overdue for a major earthquake. Does that mean ‘the big one’ is coming?—About 45% of the faults analyzed for California are running behind schedule for a major earthquake, meaning… www.sfchronicle.com/science/arti... @jackjlee.bsky.social @sfchronicle.com

Study says California is overdue for a major earthquake. Does that mean ‘the big one’ is coming?

A new earthquake study reported that a large share of California faults have been running “late,” based on the expected time span between damaging temblors.

www.sfchronicle.com

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Lucy Jones @drlucyjones.bsky.social · May 13

It is so cool to see actual fault offset, but I am also struck by how small the shaking is. This is the ultimate "near-field" site, but the shaking is not enough to topple any of the tall vases.

Dr. Wendy Bohon @drwendyrocks.bsky.social · May 12

Watch the ground break and move during the magnitude 7.7 #Myanmar #earthquake. This footage shows the incredible power of the earthquake that devastated parts of Myanmar and #Thailand. My thoughts are with the people impacted by this event. 💔

🧪⚒️

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Lucy Jones @drlucyjones.bsky.social · May 12

I see it now. I was looking in the foreground and completely missed it. Maybe 2-3 meters?

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Lucy Jones @drlucyjones.bsky.social · May 12

This doesn't look like fault movement. Notice the crack forms in the concrete but doesn't offset the edges. This looks like shaking compacted the ground under the concrete and caused a crack.

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Lucy Jones @drlucyjones.bsky.social · Apr 29

It was incredible. The OcTech singers are amazing and their music helped us metabolize our grief and anger over the fires and the attacks on science. We ended with singalongs and essentially the whole audience joined in. A good night

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Reposted by Lucy Jones

Caltech Seismological Laboratory @caltechseismo.bsky.social · Apr 25

#FieldPhotoFriday Back from the beach and up into the mountains, sometimes the field techs need to go even higher! Atop an antenna at the peak of a mountain near Lake Arrowhead to be exact! Climbing can be a regular part of the job, they do what it takes to keep the data flowing!

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Lucy Jones @drlucyjones.bsky.social · Apr 23

I've partnered with OcTech, Caltech's choral octet, to create Courage To Care: a concert & discussion to process climate angst in a time of historic fires. If you're in SoCal, come build community with us!

Sunday, April 27th, 7:30 PM
Dabney Lounge on the Caltech campus
Tickets: No tickets - free!

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Lucy Jones @drlucyjones.bsky.social · Apr 15

Interesting to look at the detailed relocations of the aftershocks to the M5.2. It looks like they are not on the main strand of the Elsinore fault.

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