iiinova — where your digital self keeps evolving

Brian Olson @brianolson.bsky.social · 08/09/2025

Tom Rockwell (Distinguished Lecture) kicking off the 2025 SCEC meeting! Small offset per event (smaller magnitude) produces narrower damage zone in nearby rocks. Serves as a proxy for max magnitude per rupture event. #scecmeet #scec2025 🧪

$Tom Rockwell standing on the stage in front of 4 chairs. On the left is a large projection screen showing one of his slides that includes a photomicrograph of fractured mineral grains.$ A slide from Tom’s talk showing an annotated aerial view of the San Andreas Fault near Little Rock and a photomicrograph on the right showing pulverized mineral grains from a sample collected several meters from the main fault plane.

A slide from Tom’s talk showing an annotated aerial view of the San Andreas Fault near Little Rock and a photomicrograph on the right showing pulverized mineral grains from a sample collected several meters from the main fault plane.

Summary slide of Tom’s talk labeled: General Summary of Physical Damage. Includes three categories: small displacement (less than 1 meter), moderate (1.5 to 2.7 meter), and large displacement (3 to 6 meters).

081

Brian Olson @brianolson.bsky.social · 08/09/2025

Opening presentation of this year’s SCEC annual meeting in Palm Springs! It seems SCEC is a “large Enterprise” working to develop & share cutting-edge earthquake system science to enhance California’s resilience & to educate and inspire future scientists. #scecmeet #SCEC2025 🧪

Digital image off the USS Enterprise from the Star Trek franchise. Small pictures of the science researchers are in little circles around the edge. The bottom of the slide says: “To boldly go where no SCEC has gone before.”

040

Brian Olson @brianolson.bsky.social · 17/04/2025

It’s me! I’m “one scientist”! 🧪

Screen shot of an online article from the Los Angeles Times about this week’s magnitude 5.2 earthquake and the early warning notifications. The text says, “Geologists at the California Geological Survey’s office in Los Angeles also received early warning notifications on their phones ‘so we were prepared for some shaking,’ one scientist posted on social media.”

020

Brian Olson @brianolson.bsky.social · 14/04/2025

Us geologists here at the @cageosurvey.bsky.social LA office all got our early warning notifications on our phones so we were prepared for some shaking. Did you get one too? Download @myshakeapp.bsky.social to be ready next time. #earthquake

Screenshot of MyShake notifications for a magnitude 5.8 earthquake (later revised to 5.2) in San Diego County. The alert reads: “Earthquake - Drop, cover, hold on. Mag 5.8 EQ in San Diego Country Estates, CA 92065, USA on 4-14-2025 at 10:08am PDT”.

A second alert under the first says: “Earthquake Alert
Earthquake Detected! Drop, Cover, Hold On. Protect yourself. - USGSShakeAlert.”

120

Brian Olson @brianolson.bsky.social · 14/04/2025

Felt the long-period shaking here in downtown LA from the M5.2 earthquake near Julian, CA (San Diego County). Epicenter is near the Elsinore Fault, which would be the primary suspect, but we'll see once more data comes in. #earthquake #Julian 🧪 @cageosurvey.bsky.social

This ShakeMap shows the ground shaking intensity from a magnitude 5.2 earthquake that occurred on April 14, 2025. The epicenter is marked with a black star and located just south of Julian, California, in San Diego County.
The shaking intensity is represented using the Modified Mercalli Intensity (MMI) scale, with colors ranging from green (light shaking) near the epicenter to blue (weak shaking) farther out. The strongest shaking (MMI V to VI) was felt in the mountains and foothill regions northeast of San Diego, including areas near Mira Mesa and Encinitas.

Seismic instrument locations are shown as triangles, and community-reported intensities are marked with small circles. Cities across Southern California and northern Baja California, including San Diego, Oceanside, Riverside, and Tijuana, experienced weak to light shaking. The scale at the bottom links MMI levels to estimated damage and ground motion levels, helping to interpret the impact across the region.

021

Brian Olson @brianolson.bsky.social · 06/04/2025

So encouraged by everyone we saw at the Hands Off rally yesterday in Santa Ana (Orange County)! #HandsOff Rise Up. Wise Up. Eyes Up.

A crowd of protesters at a rally. One of them is holding up a black sign with an outline of the United States with the words “Rise Up!” written inside.

A group of protestors on the sidewalk. One is holding a cardboard sign that reads “It’s so bad, introverts are here! Hands off our Constitution.”

A woman sitting on the curb with a white sign that reads “Thisis just not OK!”

050

Brian Olson @brianolson.bsky.social · 05/04/2025

Heading out to our local Orange County Hands Off rally shortly. #handsoff

Two t-shirts, a blue one reading “ano more Kings” with a cartoon drawing of King George III sitting on a stool with bags of money from Schoolhouse Rock. The second is a white shirt with multicolored balloons on top the word “No”.

050

Brian Olson @brianolson.bsky.social · 05/04/2025

Talks went very well and a great time was had by all!

Photo of Wendy Bohon giving a presentation at the Geological Society of America, Cordilleran Section meeting in Sacramento. She is in a hotel conference room standing behind a wooden lectern with her arm lifted and extended towards the projection screen. On the screen is a map of California showing the largest potential earthquake shaking intensities for each area of the state.

Photo of Brian Olson giving a presentation at the Geological Society of America, Cordilleran Section meeting in Sacramento. He is in a hotel conference room standing behind a wooden lectern addressing the audience. A sign at the top front of the lectern reads “Holiday Inn Sacramento” and another sign at the bottom reads “The Geological Society of America”.

Title slide of Brian Olson’s presentation that reads “Liquefaction Hazard Zone Mapping in the Greater Sacramento Area, Sacramento and Yolo Counties, Northern California.” At the top left is a multi-colored version of the California gear from the state flag with text to the right that reads “California Department of Conservation, California Geological Survey”. In the lower left is Brian’s name, job title (Senior Engineering Geologist), and CGS’ social media handle of “@CAGeoSurvey”.

070

Brian Olson @brianolson.bsky.social · 04/04/2025

Anyone have any insight into why this M3.1 in the Sacramento delta is SO deep? 🧪

Map of the San Francisco Bay and Sacramento River delta and surrounding areas. A white circle is shown north of the city of Antioch representing the epicenter of a magnitude 3.1 earthquake. A white box with details about the quake is shown in the lower left corner. It states this earthquake was 13 kilometers west of Rio Vista, CA occurring at 8:37am on April 4. The hypocenter is listed at 24.6 kilometers and is highlighted in yellow for emphasis.

110

Brian Olson @brianolson.bsky.social · 04/04/2025

If you're at the GSA Cordilleran Section meeting in Sacramento tomorrow, stop by the "Earthquake Hazards in Applied Geology" session tomorrow morning and catch me and Wendy Bohon in action as we represent the California Geological Survey! 🧪 @drwendyrocks.bsky.social @cageosurvey.bsky.social

Screen shot of the Friday morning schedule of speakers with orange boxes highlighting a talk by Wendy Bohon entitled "Earthquake Science in Public Service: Working to Keep Earthquake Hazards from becoming Earthquake Disasters" at 8:00am and a talk by Brian Olson entitled " Liquefaction Hazard Zone Mapping in the Greater Sacramento Area, Sacramento and Yolo Counties, northern California" at 9:10am.

1183

Brian Olson @brianolson.bsky.social · 02/04/2025

Example from La Cañada showing progressive residential development on an alluvial fan that has seen numerous debris flow flooding. Risk is changing with a warming climate, hazard is increasing with expanding construction. 🧪 #CDGSA2025 @cageosurvey.bsky.social

PowerPoint slide showing different topographic maps of one area of La Cañada showing more homes being built over time from 1928 to 2009. In 1928 the area is very lightly populated with scattered homes and by 2009 every lot is filled with homes and other buildings.

010

Brian Olson @brianolson.bsky.social · 02/04/2025

Jeremy Lancaster (California State Geologist) giving the lunchtime lecture at GSA on post-wildfire flooding & debris flow hazards. Highly developed alluvial fans are most prone. Studies find a minimum flow depth of 5 feet equaled total destruction of structures. @cageosurvey.bsky.social

California state geologist Jeremy Lancaster stands behind a podium speaking into the microphone giving a presentation.

Title slide of Jeremy Lancaster’s talk reading “Post-Fire geohazard management in California’s warming climate”.

141

Brian Olson @brianolson.bsky.social · 29/03/2025

The USGS posted their aftershock forecast and they are saying there's a 40% chance of another M6+ earthquake in the next week. Certainly, there will be dozens to hundreds of smaller M4s and M5s. If you are in Bangkok, I doubt you'll feel quakes less than M6 though. Scary no matter what though.

USGS "Aftershock Forecast" graph for the recent magnitude 7.7 earthquake near Mandalay in Myanmar (Burma). According to the graph, in the next week, there is a 6 percent chance of another M7+ earthquake, 40% chance of a magnitude 6+ quake, and 97 percent chance of a magnitdue 5+ quake.

131

Brian Olson @brianolson.bsky.social · 14/03/2025

That's one way to start your weekend! A M4.6 earthquake shook the Bombay Beach/Salton Sea area this morning, just before 10:30am local time. This part of California has been rumbling with small M1-2 quakes since March 1. This could be the main shock of that sequence. #earthquake 🧪

Map of southern California and part of western Arizona showing geographic features, city names, major freeways, and dark gray lines representing known surface faults. Two orange circles represent recent earthquake epicenter locations. The northerly one is the magntiude 4.6 earthquake from this morning. It plots within the southern end of the Salton Sea in Imperial County.

220

Brian Olson @brianolson.bsky.social · 08/03/2025

Post-workshop brainstorming session. 😉

Stainless steel beer tanks inside a warehouse at Rogue Brewing.

110

Brian Olson @brianolson.bsky.social · 08/03/2025

Excellent 1-day workshop in Newport, OR discussing ground failures from past Cascadia earthquakes and planning for future ones.

Vertical banner in an interior hallway. It reads: “CRESCENT Cascadia Region Earthquake Science Center, Innovative Science for a Resilient Society”

Exterior view of a vertical tsunami evacuation structure at the Hatfield Marine Science Center. A metal sign on a wooden post reads “Tsunami Evacuation Route” and points towards a concrete ramp that leads to the top of a 3-story building.

View of a marina with scattered boats and a steel arch bridge in the distance at sunset.

Elevator button panel with a button labeled “Seismic” and one with a “Tsunami Evacuation Route” sticker next to it.

360

Brian Olson @brianolson.bsky.social · 05/03/2025

Also, not the first cane raised in Congress, but this is to defend the honor of the poor and vulnerable, not wealthy elite slaveholders.

Political cartoon depicting the 1856 beating of Massachusetts Senator Charles Sumner by South Carolina Representative Preston Brooks at his desk days after giving a lengthy, excoriating speech against slavery and Congressional slaveholders. Sumner was beaten bloody and unconscious.

020

Brian Olson @brianolson.bsky.social · 22/02/2025

Quite the shimmy-shaking going on in central California, east of Salinas. This location is near where the San Andreas Fault transitions from the "locked" northern section to the middle "creeping" section. 19 earthquakes since 9pm-ish last night w/ a M3.9 being the largest. #earthquake 🧪

Map of central California, showing major cities including Salinas, San Jose, and Fresno. Dark gray lines represent know surface faults capable of generating earthquakes. Red circels represent epicenters of earthquakes that occurred within the last hour, orange circles are epicenters of quakes that happened within the last 24 hours.

041

Brian Olson @brianolson.bsky.social · 17/02/2025

LOVE “The Californians” ad for VW!! Although, unless they are coming San Diego/southern Orange County or Santa Clarita, they’re not taking the 5 to the 405 to the 10 to get to Malibu.

010

Brian Olson @brianolson.bsky.social · 13/02/2025

Here we go again!! A M3.7 earthquake just now near/on the Hayward Fault. Simmer down now! #earthquake 🧪

Shaded relief map of the San Francisco Bay Area and regions with dark gray lines representing mapped surface faults. A large red circle depict the most recent epicenter of today's earthquake sequence and they all plot very close to the mapped trace of the Hayward Fault. A table on the left lists magnitude 3.7, 3.2, 3.3, and 2.7 quakes have occurred in this area since 5:00am this morning local time.

040

Brian Olson @brianolson.bsky.social · 13/02/2025

Based on numerous paleoseismic studies along the Hayward Fault, we know large, ground-rupturing earthquakes happen about every 150 years. The last major event was a ~M6.8 quake in Oct. 1868, which was... [checks notes]... over 156 years ago. This is why we need to be alert & prepared. 🧪 #earthquake

Annotated timeline of major earthquakes on the Hayward Fault marked by yellow stars for the approximate year of the quake on the timeline. The labeled years are 1134, 1317, 1475, 1629, 1725, and 1868. Corresponding intervals between earthquakes are listed above the timeline and the intervals between major earthquakes are colored bars
that range from 97 to 183 years in between major earthquakes. Major world hisotry events are noted by black arrows on the bottom of the timeline. These include signing the Magna Carta, Black Plague in Europe, Columbus reaches the New World, California missions founded, and the 1906 San Francisco Earthquake. This figure was created by the US Geological Survey.

120

Brian Olson @brianolson.bsky.social · 13/02/2025

Earlier this week, the San Andreas Fault popped off a few M3 quakes. Today the Hayward Fault is trying to get some attention with M3.2 and M3.4 earthquakes. Can we just NOT? #earthquake 🧪

Shaded relief map of the San Francisco Bay Area and regions with dark gray lines representing mapped surface faults. Two closely spaced red circles depict the epicenters of today's earthquakes and they plot very close to the mapped trace of the Hayward Fault. A table on the left lists magnitude 3.2, magnitude 3.4, and magnitude 2.7 quakes have occurred in this area since 5:00am this morning local time.

160

Brian Olson @brianolson.bsky.social · 10/02/2025

Couple minor quakes (M3.5 and M3.0) just now near/on the San Andreas Fault, north of San Bernardino, CA. Let's all be cool and not get too rumbly, m'kay? 🧪 #earthquake

Shaded relief map of southern California showing active surface faults with dark gray lines, freeways with thick pale red lines, and labeled cities. A red circle near the city of Highland marks the epicenter of the magnitude 3.5 earthquake.

Text summary of the Caltech/USGS Southern California Seismic Network algorithm for the magnitude 3.5 earthquake. The analysis gives a 43 percent chance this earthquake was on the San Andreas Fault. Alternatively, the summary states there is a 55 percent chance it was on another fault in the Community Fault Model (CFM) and a 2 percent chance it was on a fault not in the CFM.

040

Brian Olson @brianolson.bsky.social · 09/02/2025

The USGS estimates strongest felt shaking only reached the “Light shaking” level. This is because the epicenter was so far offshore. It’s the same reason the initial magnitude was off. Hardly any offshore seismic stations, only land-based ones farther away. #earthquake 🧪

Table of “felt shaking” estimates from the magnitude 7.6 earthquake in the Caribbean Sea. Categories span “Not Felt” to “Extreme”. Highest felt shaking from this event was “Light”.

120

Brian Olson @brianolson.bsky.social · 09/02/2025

This earthquake is very likely on the primary transform plate boundary (Motagua Fault), which slides side-to-side and isn’t the kind of fault that forms large tsunamis. Because of its location, i expect most who feel it will only feel weak shaking. #earthquake 🧪

Tectonic map of the Caribbean Sea and islands. Map shows major plate boundaries (dotted lines) and major cities and countries labeled. Today’s earthquake was on the westernmost portion of the northern boundary fault.

121

Brian Olson @brianolson.bsky.social · 08/02/2025

Whoa! M7.6 earthquake in the Caribbean Sea, between Cuba and Belize. Tsunami threat to coasts and island within ~600 miles of the epicenter. #earthquake 🧪

Map of the western Caribbean Sea showing the Cuba, Belize, the state Florida and other areas. A large white dot represents the epicenter location and text below it states it was a magnitude 7.6 earthquake that was 209 kilometers from George Town, Cayman Islands.

153

Brian Olson @brianolson.bsky.social · 23/01/2025

Morning shake up down in northern Baja/southern California from a M4.2 earthquake. Epicenter is a little NW of the 2010 El Mayor-Cucapah earthquake epicenter. Did you feel it? Fill out this anonymous survey about your experience. 🧪https://earthquake.usgs.gov/earthquakes/eventpage/ci41034376/tellus

Shaded relief map of the border area between northern Baja California and southern California with roads, bodies of water, and surface faults shown. A red circle notes the epicenter of a magnitude 4.2 earthquake that happened at 10:08am local time, south of Mexicali, Mexico.

010

Brian Olson @brianolson.bsky.social · 22/01/2025

It's quiet...a little TOO quiet.

USGS earthquake map of the entire continental US showing not one single M2.5 or larger earthquake in the US over the last 24 hours, which is unusual.

020

Brian Olson @brianolson.bsky.social · 18/01/2025

SoCal just lost 7,000+ homes to wildfires, but once the fires are out, hazards aren’t over. 7 yrs ago I went to Montecito, CA to collect scientific data on the deadly post-wildfire debris flows that killed 25 & wrecked 100+ homes. As a rule of thumb, debris flows are more likely <5 yrs after fire.🧪

Photograph of a living room filled with about 2 feet of mud, tree branches, and debris from the 2018 Montecito debris flows. Muddy water stains the walls around the room about 4 feet high, up to the fireplace mantle. The fourth wall is missing, blown out by the force of the debris flow, allowing for the photograph of the whole room.

Photograph of a brick chimney and fireplace standing alone after the 2018 Montecito debris flows destroyed the rest of the house and carried it away. Soft, wet mud covers the ground in all directions.

Photograph of mud and debris covering part of a manicured golf course fairway with sand bunkers and dense trees in the distance. Other than the chaotic debris flow deposit, the golf course is pristine.

Photograph of an open house window looking inside to a room that is full of mud, broken wooden beams, and tree limbs. The debris partially blocks the view so that you cannot see most of the interior room. Mud has left splatter marks on the outside walls and window indicative of high velocity mud flows.

040

Brian Olson @brianolson.bsky.social · 15/01/2025

Fun! I definitely saw this phenomenon too, south of Hwy 178!

010

Brian Olson @brianolson.bsky.social · 11/01/2025

My favorite nights are when Jeopardy! has a “Geology” category!! (My second favorite is “The Bible.) Here are tonight’s clues for all my geo folks! 1/2

Jeopardy clue reading “Hydrothermal and fissure are types of these openings through which gases heated by magma pass.”

Jeopardy clue reading “Dip-slip, strike-slip, and thrust are types of these divisions.”

Jeopardy clue reading “Many rocks are named for places: Elbaite (island), Flagstaffite (city), this common volcanic rock (South American mountain chain).”

Jeopardy clue reading, “This common fossil-rich sedimentary rock is formed mostly from oceanic ooze.”

2152

Brian Olson @brianolson.bsky.social · 11/01/2025

The Getty Museum is within the newly announced mandatory evacuation area for the #PalisadesFire.

210

Brian Olson @brianolson.bsky.social · 10/01/2025

Not now, San Andreas!! WE'RE BUSY!

Map of the San Francisco Bay area showing regional active faults (black lines) and recent earthquake epicenters (red circles). There is a red circle over the line representing the San Andreas Fault, just west of the bay entrance (the Golden Gate). A table on the left lists two earthquakes, a magnitude 3.7, followed by a magnitude 2.5.

050

Brian Olson @brianolson.bsky.social · 09/01/2025

2 new fires popped up this evening. The Sunswept and Divide Fires. We're at SEVEN total fires currently burning in LA County.

000

Brian Olson @brianolson.bsky.social · 09/01/2025

This is the newly started #SunsetFire in the Hollywood Hills, just west of Runyon Canyon.

110

Brian Olson @brianolson.bsky.social · 09/01/2025

Current status in southern California. I'm not near any active fires at the moment (blue circle), but we're monitoring it all. FIVE fires currently active: #PalisadesFire #HurstFire #EatonFire #SunsetFire #LidiaFire

181

Brian Olson @brianolson.bsky.social · 08/01/2025

It's wild to see that all the damaged/burned structures by the #EatonFire in Altadena and Pasadena are down on the alluvial fan, not up in the mountains and canyons. Shows the driving force of the northerly winds. Map available here: www.google.com/maps/@34.180...

2146

Brian Olson @brianolson.bsky.social · 07/01/2025

Despite the low population density, USGS is forecasting significant loss of lives as well as financial losses. This is a strong quake, but many of these losses are tied to building quality. #earthquake

010

Brian Olson @brianolson.bsky.social · 07/01/2025

M7.1 earthquake along the Nepal-Tibet border just now. This area has a fairly low population density, but I’d expect lots of shaking-triggered landslides in this mountainous terrain. #earthquake

130

Brian Olson @brianolson.bsky.social · 30/12/2024

NEHRP-funded research continues to help safeguard lives and property, continuing Carter’s enduring commitment to disaster resilience & public safety. His vision made the nation more resilient to earthquakes & we’re continuing to learn more! Thank you & happy first day in heaven, Mr. President. 3/3

“Map of the United States from the USGS National Seismic Hazard Model, showing the probability of damaging earthquake shaking over 100 years. Areas are color-coded, with red indicating the highest risk and blue the lowest. Alaska, Hawaii, and the contiguous U.S. are displayed at the same scale. Population density is overlaid with black and purple shading to indicate areas of higher density.”

072

Brian Olson @brianolson.bsky.social · 30/12/2024

Under Carter’s leadership, NEHRP advanced earthquake understanding, improved building codes, and promoted resilient construction techniques. These efforts have significantly enhanced America’s preparedness for seismic events. 2/3

Front cover of FEMA P-2082-1 entitled, “NEHRP Recommended Seismic Provisions for New Buildings and Other Structures.” Dates September 2020.

170

Brian Olson @brianolson.bsky.social · 30/12/2024

One of my favorites of President Jimmy Carter’s many science policy accomplishments is his signing of the 1977 Earthquake Hazards Reduction Act, establishing the National Earthquake Hazards Reduction Program (NEHRP). 1/3 🧪

“Black-and-white photograph of President Jimmy Carter standing behind a desk in the Oval Office, addressing a group of reporters and photographers. Microphones and cameras are positioned toward him as he speaks, with members of the press attentively listening and capturing the moment.”

33510

Brian Olson @brianolson.bsky.social · 20/12/2024

Looks like a small earthquake sequence/swarm popped off near the southern shore of the Salton Sea last night and is still rumbling along. 40 earthquakes so far with a M3.2 being the largest so far. This is VERY common is this part of California, but we'll keep an eye on it. #earthquake

020

Brian Olson @brianolson.bsky.social · 18/12/2024

Much respect to @timblor.bsky.social for showcasing this 6'4" giant FULL of California love on the title slide of his end-of-year presentation today! #CaliforniaGold Huell Howser: "Oh BOY!"

Photograph of TV personality Huell Howser squatting down in a field of wildflowers, including orange California poppies and blue lupine, in the Carrizo Plain area on San Luis Obispo County. The text above his head reads, "California's Gold: CGS Seismic Hazards Program Year in Review" and below him is his famous cathcphrase: "That's Amazing!"

110

Brian Olson @brianolson.bsky.social · 17/12/2024

I would like TIME Magazine to reconsider their pick for “Person of the Year”.

020