Although preliminary reports pegged the quake at 6.9 on the Richter Scale, Caltech updated the data about an hour later, stating that the earthquake was closer to a 7.2. (As a frame of reference, the devastating January earthquake in Haiti was a 7.0, while Chile suffered an 8.8 quake in February.)
Within minutes of the first quake, Twitter had tens of thousands of tweets on the topic -- ahead of all the major news networks.
Pictures posted by Twitter users in Mexicali, Mexico (seen above and below) showed major damage to buildings and roads. Multiple injuries have been noted, and the quake was responsible for at least two deaths.
Felt in California, Arizona
Stateside, very little damage has yet been reported, although highrise buildings in Los Angeles and San Diego were reportedly swaying. Rides at Disneyland were closed for about an hour to ensure there was no damage, and as far away as Las Vegas and Phoenix, Arizona, water lapped over the edge of swimming pools.
Close to the Mexican border, Joel D Amos, our Entertainment Editor was in San Diego, and filed this report:
I have never felt anything like that in my life. I've felt earthquakes about 8 times since we moved here 15 years ago, and this was by far the worst. The entire house moved like a giant snake went under it for almost 45 seconds.
We were in the kitchen making a late lunch and my equilibrium is what told me first something wasn't right. I immediately went from hungry for lunch to completely seasick in the blink of an eye. Holding onto the counter for balance, I hear my wife yell, 'Look at the sink.' In the sink were dishes that were clattering together and tossing the water in them for soaking back and worth... and ultimately out and down the drain.
She quickly ran to the living room to grab one of our dogs, as I followed her to grab the second dog, who was waking up from a nap in front of an enormous bookcase that had started swerving. As I grabbed him and we started to run outside... it stopped. Then the adrenaline kicked in just in time for the 5.3 aftershock 20 miles from our house.
Near the SheKnows offices in Scottsdale, Arizona, the quake was felt as a "gentle rolling motion," with many reports of locals thinking they were lightheaded or dizzy before they realized it was an actual earthquake. Said one of our staffers, "It felt like I'd just gotten off a boat, and still felt that swaying motion in my head."
Connecticut resident Ellen Satter was visiting a restaurant near Disneyland when the earthquake hit. "At first I thought I was on a ride, then I realized I wasn't. I looked around and asked, 'Is that what I think it is?' And the guy across from me nodded," she said. "It was a gentle swaying feeling. As it petered away, it was hard to tell if it was really still happening or if I was disoriented, but the umbrellas hanging from the ceiling were still swaying."
Part of a pattern
Today's large quake was part of a string of quakes, including aftershocks measuring 5.1 and 5.4. After the biggest quake, a 4.4 earthquake hit hundreds of miles north in Santa Rosa, which is part of Northern California's Wine Country.
This 7.2 earthquake's epicenter was 16 miles from Guadalupe Victoria, Baja California, Mexico -- a region also known for its wine. The US Geological Survey (USGS) also notes that the same area has been experiencing smaller quakes in the 3.0 range for the past week.
USGS seismologist Lucy Jones said, "It sounds like it [was] felt by at least 20 million people at this point."
Updated 5 April 2010 at 1:20pm PST
Past earthquake features:
A road in Mexicali buckles after the earthquake (Photo by polyvf)
Damage to a grocery store in Mexicali (Photo by Elviiira)
Top photo by by Cimarron98