Here's how fast an earthquake shows up on Twitter

Friday, October 9, 2015, 8:20 AM - If you're in Vancouver and want to report an earthquake, you may actually be faster on the trigger than the actual experts -- provided you're on Twitter.

That's the insight you'll find on Twitter's latest Data Stories blog, where the popular microblogging site posts interviews with people who use the tool in surprising ways.

The biggest insight: The 2008 Sichuan earthquake in China made it onto Twitter before the United States Geological Survey (USGS) reported it. And that was no minor tremor, but a Magnitude 7.9 monster that left more than 87,000 people dead or missing, and millions homeless.

That may sound surprising, but it seems the USGS wasn't surprised. Most of its earthquake sensors are in the United States, leaving many places in the world uncovered by the service. Most countries have their own seismological service, but even so, the USGS is the first stop for many people, including here in Canada.

Once Twitter's speed was apparent, USGS at least partially adopted it as a quake detection tool. Just 14 tweets in Chile earlier this year allowed the service to determine an aftershock had happened. In 2014, Twitter-savvy people in California allowed the USGS to detect the Napa quake in just 29 seconds.

As Twitter's Elaine Ellis reports, though, there are a few caveats.

First, it seems tweets that contain links or references to a quake's supposed size are usually not firsthand accounts, so they're omitted from USGS' Twitter seach. So are tweets that are seven words or more, as someone in the midst of a quake likely won't be feeling too verbose.

There are even a few cultural things to watch out for, and they've even fine-tuned their system to distinguish between "temblor", which in Chile is usually taken to mean aftershock, and "terremoto", a full-on quake.

There are some gaps in Twitter's reach (when Ellis was at USGS' offices, two quakes detected in Indonesia and remote Easter Island weren't felt by enough people on Twitter for it to be a factor), but it seems most can be registered using Twitter within a couple of minutes.

So if the ground is rumbling, and after you've rushed to safety, you might actually be doing a public service by getting on your phone and tweeting "Earthquake?"

SOURCES: BBC | Twitter Data Stories