At 8:08pm, on Saturday night, two moderate earthquakes struck in the Anza-Borrego Desert. A 4.9 and 4.5 magnitude earthquake hit approximately 9 miles north northwest of Borrego Springs, California. Both earthquakes occurred just south of the Anza Gap and are related to San Jacinto Fault.
The first earthquake was a 4.9 magnitude quake which struck at 8:08pm.
The second earthquake was a 4.5 magnitude aftershock that struck at 8:09pm.
Because the earthquakes struck so close together, only 24 seconds separated the two seismic events, the USGS had trouble determining the exact magnitude, location, and whether they had one or two events recorded. Within the first hour, the magnitudes were revised multiple times and the sizes ranged from 4.4 to 4.9 in magnitude.
At the time of this posting, the official answer seems to be that two quakes occurred, a magnitude 4.9 and a 4.5.
The epicenter of both quakes were far from any major town. Anza and Borrego Springs were the closest towns to the epicenter, both small desert communities. The San Diego Union Tribune quoted a clerk at the Borrego Springs Resort as saying, "...the building’s glass shook but did not break, and the resort had no damage." No damage or injuries were expected elsewhere as well.
Despite the quake being considered small to moderate, it was widely felt strongly by many in Imperial, San Diego, Orange, and San Bernandino county areas, as well as by people in the Los Angeles city area. Additionally, felt reports were received from Tijuana, Tecate, and Mexicali, Mexico.
Some of the communities that turned in the most felt reports included Carlsbad, Ramona, La Quinta, Santee, Escondido, San Diego, Poway, Encinitas, Temecula, San Marcos, Fallbrook, Palm Desert, Murrieta, and Oceanside.
I personally felt this quake while I was at work in Carlsbad, California. I was in an office building at the time, ground floor, in a hallway when the earthquake struck. It felt like something hit the building. The entire building suddenly shook violently. I stopped what I was doing and looked down the hallway. I heard the shaking travel through the building from one side to the other, east to west. I knew immediately that it was an earthquake. However, after the initial jolt, I could not feel any shaking afterward and no apparent damage had been done.
The following recording was made back home while I was at work. I have set up an earthquake cam in an attempt to capture a quake on video. Unfortunately, there is no sound, but what you will see is at least three things move in the shot. (According to the clock in the video) At 8:07pm and 49 seconds, the p-wave hits, effecting the chimes and the pendulum. A 8:07pm and 59 seconds, the pendulum and the ball move, almost in unison. You have to watch for the ball closely, though. It's very subtle. For the remainder of the video, the chimes and pendulum shake until they eventually calm down.
[Magnitudes and locations are subject to change as the USGS continues to review the data.]
-Article written by Tim "Lance" Sherwood of Oceanside, Ca.
Showing posts with label san diego. Show all posts
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At 4:02am, on Wednesday morning, a 3.1 magnitude earthquake hit 6 miles southeast of Ocotillo, California. The earthquake occurred just north of the Mexican border, in the desert, and is possibly related either to the Yuha Wells Fault or the extreme northern edge of the Laguna Salada Fault. The earthquake appears to be an aftershock of the 7.2 Baja earthquake sequence.
A 1.9 magnitude aftershock was detected just two minutes later.
The 3.1 magnitude earthquake was not reported as felt by anyone to the USGS.
The epicenter of the 3.1 quake is located in the desert where no major towns are immediately nearby. Due to the minor magnitude and rural terrain, no damage or injuries are expected.
The closest communities are Ocotillo, Ocotillo Wells, Jacumba, Seeley, Calixico, Mexicali, Santa Isabel, El Centro, Brawley, Plaster City, and the closest major US city is San Diego.
[Magnitudes and locations are subject to change as the USGS reviews the automated data.]
A 1.9 magnitude aftershock was detected just two minutes later.
The 3.1 magnitude earthquake was not reported as felt by anyone to the USGS.
The epicenter of the 3.1 quake is located in the desert where no major towns are immediately nearby. Due to the minor magnitude and rural terrain, no damage or injuries are expected.
The closest communities are Ocotillo, Ocotillo Wells, Jacumba, Seeley, Calixico, Mexicali, Santa Isabel, El Centro, Brawley, Plaster City, and the closest major US city is San Diego.
[Magnitudes and locations are subject to change as the USGS reviews the automated data.]
At 11:10am, on Thursday morning, a 4.1 magnitude earthquake hit 6 miles east southeast of Ocotillo, California. The earthquake occurred just north of the Mexican border, in the desert, and is possibly related either to the Yuha Wells Fault or the extreme northern edge of the Laguna Salada Fault. The earthquake appears to be an aftershock of the 7.2 Baja earthquake sequence.
Earlier in the morning, a 3.2 earthquake occurred near Anza and a 3.1 earthquake occurred near Salton City, California. These three earthquakes occurred within 10 hours of each other and, two months after the Baja quake, this is showing signs that seismic activity in the region is not going quiet just yet.
The 4.1 magnitude earthquake was felt as far north as Palm Springs, as far northwest as Irvine, as far west as San Diego, as far east as Mexicali, and south into Mexico.
The epicenter of the 4.1 quake is located in the desert where no major towns are immediately nearby. Due to the moderate magnitude and rural terrain, no damage or injuries are expected.
[Magnitudes and locations are subject to change as the USGS reviews the automated data.]
Earlier in the morning, a 3.2 earthquake occurred near Anza and a 3.1 earthquake occurred near Salton City, California. These three earthquakes occurred within 10 hours of each other and, two months after the Baja quake, this is showing signs that seismic activity in the region is not going quiet just yet.
The 4.1 magnitude earthquake was felt as far north as Palm Springs, as far northwest as Irvine, as far west as San Diego, as far east as Mexicali, and south into Mexico.
The epicenter of the 4.1 quake is located in the desert where no major towns are immediately nearby. Due to the moderate magnitude and rural terrain, no damage or injuries are expected.
[Magnitudes and locations are subject to change as the USGS reviews the automated data.]
At 8:52 pm, a 3.6 magnitude earthquake hit 11 miles west southwest of downtown San Diego.
At 8:57pm, a 4.3 magnitude earthquake hit 38 miles southwest of Imperial Beach.
Both earthquakes hit 5 minutes apart and both were off the coast of downtown San Diego. This is a change in activity as both quakes occurred far from the Baja aftershock sequence. There were no immediate reports of damage or injuries and none would be expected due to the moderate to low magnitude of both quakes.
The magnitudes and locations are subject to change as the USGS reviews that data.
The last earthquake in this region was a 3.5 magnitude quake 36 miles southwest of Rosarito, Mexico, on March 24, 2010.
Before that, there was also a 4.4 and two 3.6 magnitude earthquakes between February 1st and February 3rd earlier this year in the same general location off the coast.
At 8:57pm, a 4.3 magnitude earthquake hit 38 miles southwest of Imperial Beach.
Both earthquakes hit 5 minutes apart and both were off the coast of downtown San Diego. This is a change in activity as both quakes occurred far from the Baja aftershock sequence. There were no immediate reports of damage or injuries and none would be expected due to the moderate to low magnitude of both quakes.
The magnitudes and locations are subject to change as the USGS reviews that data.
The last earthquake in this region was a 3.5 magnitude quake 36 miles southwest of Rosarito, Mexico, on March 24, 2010.
Before that, there was also a 4.4 and two 3.6 magnitude earthquakes between February 1st and February 3rd earlier this year in the same general location off the coast.
A 3.8 earthquake centered along the California and Mexico border just south of San Diego has been felt throughout San Diego county. The quake struck at 11:53 PM on September 2, 2005.
I was able to capture this quake on video. The video clip is not very exciting and not much to see. But I am excited because it has already answered several questions I had. It will help in my research.
This is the first quake to be captured using my new "Klesko Cam".
Let me take a moment to explain what we are seeing on the video clip. First of all, the quake was heard before it was felt. As the video begins you will hear that I am watching the baseball game. I heard a loud roaring sound coming from outside. I stopped the TV. This is when the sound of the ball game stops. If you have a good sound system with a sub woofer you should be able to hear the deep roaring sound. At the same time you can see Ryan Klesko's head vibrate ever so slightly. Five seconds later the S waves (shear waves) arrived and you can see and hear the small jolt.
The loud whistling/ringing you hear is the quake alarm sounding. The quake alarm is a very sensitive device which detects seismic waves. This quake was rather small and the P waves (which was the loud roaring sound and slight vibration) were too slight to activate the alarm. The slower moving and more destructive S waves arrived five seconds later, when we heard the quake alarm.
ABOUT KLESKO CAM
Klesko Cam is designed to record a visual and audio record of earthquakes. The scene is a hodgepodge of household junk. In theory here is what we should be able to see:
First, we should hear the quake alarm start sounding. At the same time we may see Ryan Klesko's head start vibrating. The strength of the P wave vibration will be determined by the strength of the quake.
Next, we wait for the arrival of the S waves. The "S" or Shear Waves travel slower than the P waves. The timeframe between the "P" waves and the "S" waves are determined by how far away we are from the epicenter of the quake.
When the S waves arrives we should see Ryan Klesko start nodding or shaking his head (depending on the direction of the quake from our location).
If the quake is strong enough, we should see the dominoes start tumbling over. I only have one domino right now, but I'm saving up for more. I plan on setting up the dominoes in such a way that it can be determined which direction the quake came from by observing which dominoes fell and how they fell.
If the quake is even stronger, we will see the collapse of the "Diet Dr. Pepper Pyramid".
If the quake is even stronger you may see the camera start to tip over as you hear me in the background screaming and running around in a panic.
I was able to capture this quake on video. The video clip is not very exciting and not much to see. But I am excited because it has already answered several questions I had. It will help in my research.
This is the first quake to be captured using my new "Klesko Cam".
Let me take a moment to explain what we are seeing on the video clip. First of all, the quake was heard before it was felt. As the video begins you will hear that I am watching the baseball game. I heard a loud roaring sound coming from outside. I stopped the TV. This is when the sound of the ball game stops. If you have a good sound system with a sub woofer you should be able to hear the deep roaring sound. At the same time you can see Ryan Klesko's head vibrate ever so slightly. Five seconds later the S waves (shear waves) arrived and you can see and hear the small jolt.
The loud whistling/ringing you hear is the quake alarm sounding. The quake alarm is a very sensitive device which detects seismic waves. This quake was rather small and the P waves (which was the loud roaring sound and slight vibration) were too slight to activate the alarm. The slower moving and more destructive S waves arrived five seconds later, when we heard the quake alarm.
ABOUT KLESKO CAM
Klesko Cam is designed to record a visual and audio record of earthquakes. The scene is a hodgepodge of household junk. In theory here is what we should be able to see:
First, we should hear the quake alarm start sounding. At the same time we may see Ryan Klesko's head start vibrating. The strength of the P wave vibration will be determined by the strength of the quake.
Next, we wait for the arrival of the S waves. The "S" or Shear Waves travel slower than the P waves. The timeframe between the "P" waves and the "S" waves are determined by how far away we are from the epicenter of the quake.
When the S waves arrives we should see Ryan Klesko start nodding or shaking his head (depending on the direction of the quake from our location).
If the quake is strong enough, we should see the dominoes start tumbling over. I only have one domino right now, but I'm saving up for more. I plan on setting up the dominoes in such a way that it can be determined which direction the quake came from by observing which dominoes fell and how they fell.
If the quake is even stronger, we will see the collapse of the "Diet Dr. Pepper Pyramid".
If the quake is even stronger you may see the camera start to tip over as you hear me in the background screaming and running around in a panic.
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