Earthquakes at Sea Ranch?!
If you’ve spent time in California, especially along the coastal regions, then you most likely have felt it…EARTHQUAKE!
So as you get ready to book your vacation rental you may be asking yourself, “Sea Ranch is on the coast, does that mean we could have an earthquake here too🤔…😳…😱?”
Yes, indeed, it does! In fact, last year on December 12, 2022 a strong 6.4 earthquake ocurred 216 miles away and was felt in Whalebone Reach, Sea Ranch. The owners reported their “house shifted slightly.” Others noted that their dog woke them up just as it was about to happen.
On January, 28,2021 there was a small rumble (magnitude 3.7) near Point Arena. The United States Geological Survey detected the quake at 8:25 a.m. with an epicenter 30.7 miles southwest of Point Arena, California. With a magnitude of 3.7 and depth of 2.49 miles, this quake could be felt near the epicenter but no damage was reported.
Not to Worry!… Much😉
We can report the low number of earthquakes that occur in our immediate area are not strong …so far.
The USGS database reported on Homefacts shows that there is a 74.17% chance of a major earthquake within 50km of Sea Ranch, CA within the next 50 years. The largest earthquake within 30 miles of Sea Ranch, CA was a 4.4 Magnitude in 2001. But if you are not used to them one may be one too many.
Nonetheless, after living through the 3 minute long Chilean 8.8 earthquake in 201o, our family rarely flinches at anything under a 6.0 magnitude.
I guess it just takes practice 🤪.
The San Andreas Fault
The San Andreas Fault is the sliding boundary between the Pacific Plate and the North American Plate. It slices California in two from Cape Mendocino to the Mexican border. San Diego, Los Angeles, and Big Sur are on the Pacific Plate. San Francisco, Sacramento, and the Sierra Nevada are on the North American Plate. And despite San Francisco’s legendary 1906 earthquake, the San Andreas Fault does not go through the city. But communities like Desert Hot Springs, San Bernardino, Wrightwood, Palmdale, Gorman, Frazier Park, Daly City, Point Reyes Station, and Bodega Bay l
After the San Andreas Fault leaves San Francisco, it plays tag with the California coast. The fault comes ashore at the Point Reyes Peninsula, Bodega Bay where they lie squarely on the fault and are sitting ducks, then at a stretch of the coast from Fort Ross to Manchester Beach. The rocks in this last segment are mostly sedimentary and were deposited in the Gualala Basin during late Cretaceous to Miocene time. We don’t know exactly where the Gualala Basin was when it started its trip north, but it was probably somewhere in southern California or Baja California.
Explore the Sea Ranch Earthquake Trail
One of our six self-guided Interpretive Trails is that of the San Andreas Fault Trail (pdf). The trailhead is located just above the Hot Spot on River Beach Road. Swales and hummocks (created by parallel faults) comprise the four ridges. Delight in the discovery of a sag pond. And make note of the broken trees and displaced/recaptured drainage channels from 1906 and earlier earthquakes. The trail also features historical remnants from 1890’s logging of original ancient redwoods (such as springboard notches and skid trails), as well as forest ecology of unique overstory, understory, and ground cover, as well as stump islands colonized by redwood sorrel (oxalis). Park at the Hot Spot and walk up River Beach Road to the trailhead.
Learn more about the Geology of the Sea Ranch and the San Andreas Fault
Geologic Background, Sea Ranch
Places to See the Rocks
For the earthquake buff or rock hound, these trips within Sea Ranch may be the perfect vacation activity. Below are three areas you may want to explore in greater depth. The Pdfs attached here will help guide you and provide you with added information to make your discoveries more meaningful.
- Bluff (pdf): A geologic trip along the Sea Ranch bluff provides a good opportunity to visit these well-traveled rocks.
- Meadows and Hillside Terraces (pdf): The meadow and hillside at the Sea Ranch have been sculptured by wave action to form a series of wave-cut terraces during the last 500,000 years.
- San Andreas Fault in Sea Ranch: Walk along the San Andreas fault at the Sea Ranch and see ridges and sag ponds that were formed by movement along the fault.
- San Andreas Fault in Sea Ranch and Bowling Ball Beach, by Ted Konigsmark
It is important to remember, The Sea Ranch is private property. Non-residents should contact the Sea Ranch Association for access. However, as a guest of Abalone Bay enjoy your hike and exploration. Just pack your guest pass, your parking tag, a few snacks, and a water bottle. Oh and don’t forget your camera and geologic notebook too!
What to Do In Case of an Earthquake
Sonoma County is bounded on the west and the east by earthquake faults. For your emergency information, there are four active or potentially active earthquake faults are identified within the County’s boundaries.
If you are inside, stay inside.
DO NOT run outside or to other rooms during an earthquake. You are less likely to be injured if you stay where you are.
Reduce your chances of being hurt
To reduce injury take the following actions:
- If possible, within the few seconds before shaking intensifies, quickly move away from glass, hanging objects, bookcases, china cabinets, or other large furniture that could fall. Watch for falling objects, such as bricks from fireplaces and chimneys, light fixtures, wall hangings, high shelves, and cabinets with doors that could swing open.
- If available nearby, grab something to shield your head and face from falling debris and broken glass.
- If you are in the kitchen, quickly turn off the stove and take cover at the first sign of shaking.
- If you are in bed, hold on and stay there, protecting your head with a pillow. The likelihood of injury lessens by staying where you are. Broken glass on the floor can cause injuries if you walk or roll onto the floor.
DO NOT stand in a doorway. You are safer under a table.
In modern houses, doorways are no stronger than any other part of the house. Doorways do not protect you from the most likely source of injury − falling or flying objects. Most earthquake-related injuries and deaths are caused by falling or flying objects (such as TVs, lamps, glass, or bookcases), or by being knocked to the ground.
Move away from buildings, utility wires, sinkholes, and fuel and gas lines.
The greatest danger from falling debris is just outside doorways and close to outer walls of buildings. Go to an open area away from trees, telephone poles, and buildings. Once in the open, get down low and stay there until the shaking stops.
Prepare Now
California’s probability for a large quake is 99% in the next 30 years. For that reason we recommend you prepare your home and yourselves. When staying at a vacation rental, don’t hesitate to ask the owner or property manager how they have prepared the home your at too.
Below are tips and resources for you:
- Secure bookcases, televisions, and objects that hang on walls. Store heavy and breakable objects on low shelves.
- Practice Drop, Cover, Hold with family and coworkers.
- Create a family emergency communications plan that has an out-of-state contact.
- Plan where to meet if you get separated. Choose 2 locations:
- One close to home, and
- A central location that is manageable based on where your family works, goes to school, and plays.
- Be sure you have a home emergency kit with everything you need for at least 7 days.
- Learn more about building a survival kit
- Consider obtaining an earthquake insurance policy.
- Learn more about Earthquake Safety for Homeowners
- Consider a retrofit of your house to correct structural issues.
- For help and advice, see the Sonoma County’s Energy and Sustainability website.
- Now available, MyShake, app for your phone. Get notifications about nearby earthquakes and track earthquakes around the globe. Quickly understand what damage and shaking reports from USGS and community reporting. Your participation helps collect valuable data from the earthquake.
- More information: Staying safe where the earth shakes
Other Websites and Resources
Sonoma County Regional Parks:
Aerial Photographs of the California Coastline:
US Geological Survey:
For further resource visit Information http://www.geologictrips.com/index.htm
Leave a Reply