The Anatomy of a Los Angeles Earthquake… on Twitter

The July earthquake in LA caused chaos in the shampoo & conditioner aisles...

Sitting at my desk at 7:42pm (Friday), doing some research on the web (read: procrastinating), I felt something odd. It was as if somebody walked behind my chair, shunting me forward slightly. I turned, and of course no one was there. Slightly confused, I heard my wife shout from the living room, “Did you feel that?” Then I knew I wasn’t dreaming, there had been an earthquake.

That wasn’t my first experience of a quake, back in July 2008, Woodland Hills felt a seismic wave from the magnitude 5.4 earthquake epicentre near Downtown LA. That’s the only way I can describe it, a rolling wave. We were outside at the time, and I was amazed to see the water in the pool slosh over the sides. Now that was my first quake, and I found it pretty exhilarating (as I ran inside to get my video camera to take an eyewitness account of any other tremors, but there were no more to follow).

Today’s was a short and pretty wimpy magnitude 3.4, just a tiny burst of energy. However, interested to find out more, I turned to one of the best breaking news resources out there, Twitter…

A frame from the USGS animation of the seismic activity around the LA region, including today's quake (click image to see the full animation)

Watching breaking news unfold on Twitter is like listening to a Geiger counter click as it is held near a radioactive source; the first clicks are just background noise, but then a surge of clicks scream radioactivity. And that is pretty much what happened earlier this evening.

There was some low-level chatter on Twitter about a news article put out by the LA Times today, entitled “Major earthquakes on San Andreas happen more frequently than previously thought,” and then, through a case of Murphy’s Law, LA feels a magnitude 3.4 quake as a reminder that Southern California’s faults are alive and well.

Literally 30 seconds after I felt the chair-jerking quake, I saw the word “earthquake” explode to existence in the TwitScoop panel of TweetDeck. I clicked the keyword to try and work out where the epicentre may have been. The very first tweet about the earthquake was a fast-fingered Cindy, seconds after the rumble:

“Earthquake?? Again? Are you serious ???!“ — HeyCindy, 7:43pm (Friday)

However, this tweet didn’t reveal much. As the seconds moved on, a flood of tweets appeared in the TwitScoop feed, and I started tweeting my location and that I had felt the earthquake too.

The profile of an earthquake on Twitter (TwitScoop)

Eventually, a picture had formed, and through eyewitness tweets, the community had narrowed the location of the epicentre down to the Santa Monica/Venice area. Most of the tweets were, obviously, not of much use to the investigation, but a few were entertaining:

“Just rode out an earthquake at a sushi bar in SoCal! At first I thought the sake had gone to my head” – lkreitler

“3.4 earthquake nearly knocked me on my ass while blow drying my hair” – laila_astri

“The earth didn’t move for me…maybe that’s good what with me being single and all.” – rainydaydiamond

But then we have a breakthrough, only six minutes after the earthquake, blackfeathers forwards the U.S. Geological Survey website with information on the LA earthquake. On opening, I found that the initial reports from Twitter weren’t that far from what had actually happened. Of course one could argue that it is luck that a few Twitterers are going to be right, but there did appear to be a clustering of reports from the Santa Monica area, and the USGS confirmed this:

Earthquake details (distances):
2 km (1 miles) WNW (288°) from Marina del Rey, CA
4 km (3 miles) SSE (166°) from Santa Monica, CA
7 km (4 miles) WSW (248°) from Culver City, CA
12 km (7 miles) WNW (285°) from Inglewood, CA
22 km (14 miles) WSW (249°) from Los Angeles Civic Center, CA

–USGS

For full information on today’s magnitude 3.4 LA earthquake, check out the US Geological Survey pages.

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So, this little event got me thinking. Perhaps Twitter is a more useful tool that I originally thought… If a small quake in LA can be tracked with this kind of accuracy, within seconds of the event, suddenly microblogging becomes a force to be reckoned with. I’ve been toying with the idea of some form of social earthquake detection system, but this would only work in populated regions. In any case, Twitter has just become my preferred method of being alerted to breaking news.

And the mainstream media is only just beginning to report the news, hours after the event…