In what has become a too-familiar experience in Tokyo, a crowded subway train screeches to a sudden halt. From around the car, mobile phones start to ring.

　　乘坐拥挤的地铁时发生地震在东京是再寻常不过的事情了。在地铁急刹车时，车厢内各个角落的手机开始响起来。

　　The sound is an emergency earthquake warning from an iPhone app that lets subscribers know when the quake will come, where the epicenter will be located and how strong the shaking will be. Often, seconds after the phone rings, the shaking starts.

　　这一响声是iPhone的一款应用程序发出的紧急地震警报，让用户知道地震何时会来临，震中在哪个位置，以及地震强度有多大。通常，手机响后几秒钟，地震就会开始。

　　Following the devastating March 11 earthquake and tsunami, which have left nearly 28,000 dead and missing, Japan has been hit by hundreds of aftershocks of varying strengths.

　　在3月11日发生强震和海啸之后，日本已发生数百次强度各异的余震。这次强震和海啸已导致近2.8万人死亡或失踪。

　　The app called Yure Kuru, or shaking coming, was developed by RC Solution Co, a Tokyo-based firm that specializes in providing disaster-related information services, such as relaying warnings or letting people confirm the safety of friends and family.

　　这款应用程序名为Yure Kuru（地震来了），是由一家专门提供灾害信息服务的日本公司RC Solution研发的。该公司提供转发警报或帮助确认亲友的安全等服务。

　　"Emergency quake warnings began several years ago, but the equipment to receive them was quite expensive," said Akira Kuriyama, president of RC Solution.

　　RC Solution的总裁栗山明说：“紧急地震警报在几年前就有了，但是接收警报的设备相当昂贵。”

　　"We wondered if there wasn't a cheaper and easier way to provide this service, and we thought of smartphones."

　　“我们想知道是否有更廉价、更容易的方式来提供这一服务，于是我们想到了智能手机。”

　　The app, based on technology originally developed by Japan's Meteorological Agency and railway firms, was released in November 2010.

　　 这一应用程序基于日本气象厅和铁路公司研发的技术，于2010年11月发布。

　　When the alarm is triggered, a window comes up on the phone screen saying that in approximately 10 seconds, there will be a quake of a certain strength. Users can decide for themselves at what strength of quake the phone will ring.

　　在警报响起时，手机屏幕上会弹出一个窗口，上面的文字显示说，大约在10秒后，会发生一定级别强度的地震。用户可以自行设定在发生何种强度的地震时手机会响起。

　　Prior to March 11, there were 100,000 subscribers, Kuriyama said. But now there are at least 1.5 million, and the company has stopped counting.

　　栗山说，在3月11日前，用户数为10万，而现在至少有150万用户。由于用户太多，公司已经停止计算用户数。

　　The app is symbolized by a cartoon catfish, which, according to Japanese folk belief, are said to warn of quakes.

　　这一应用程序的标志是一条卡通鲶鱼。据日本民间的说法，鲶鱼可以预报地震。

　　"We're very happy to be of service," Kuriyama said. "Among other things, there still isn't a lot of understanding about the quake warning. If our app helps more people learn about this, and increases their safety, we'll be pleased."

　　栗山说：“我们很高兴能对大家有所帮助。另外，人们在地震预警方面了解得并不多。如果我们的应用程序能够让更多的人对此有所了解，并让人们更安全，我们会很高兴。”