Twitter and social networks were a key part of communications during Japan’s tsunami and earthquake disaster last year. Indeed, user numbers for Twitter and domestic site Mixi got a huge boost as those affected, seeking updates or just following events, turned to social media to keep up with developments in real-time.

Fast forward more than a year and Twitter and smartphones remain at the core of Japan’s emergency contingency plans, as was illustrated yesterday when Twitter, Yahoo Japan and domestic real estate firm Mori clubbed together to test the potential of mobile apps and the microblogging platform in disaster situations.

The Japan Times reports that 100 volunteers from Tokyo’s Rappongi district were selected to take part in a drill that simulated a major earthquake.

The paper explains the real-time communications system that was used to keep people up to date and help them distinguish between correct and erroneous information:

The participants simultaneously received the initial quake report via a smartphone app for emergency alerts provided by Yahoo before moving to a shelter set up by Mori Building Co.

The drill required frequently checking Twitter updates issued by Mori Building on appropriate evacuation routes and also tweeting on the whereabouts of any injured people encountered on the way.

Twitter is already a popular method for sharing information about earthquakes and tremors in the Japanese capital city. The country is subject to a large number of earthquakes and, in response, a dedicated quake bot — @earthquake_jp — has emerged, and it is closing in on 1 million followers.

japan quake 520x275 Twitters emergency service potential tested in Japanese earthquake drill

Regular Japan-based Twitter users also take to the service to discuss shakes, tremors and the quake-related updates.

Twitter has an estimated 18 million registered users in Japan.

Image via Flickr /  CECAR – Climate and Ecosystems Change Adaptation R