Earthquake Notification Service (ENS) is a free service that provides earthquake alerts happening around the World. This program is managed by the U.S. Geological Survey organization and is free to everyone.

Earthquake information are available by country/region wise. You can subscribe @USGSted on Twitter for worldwide earthquake notifications with magnitudes of 5.5 and above. Various RSS feeds are also available for earthquakes, Landslides and Volcano Updates.

A Google gadget is also available for USGS real-time earthquake notifications. It can be added to your iGoogle home page.

Subscribing only for Specific Area

If you are interested in receiving notification only for your desired area you can do so as well. For this you have to register at Earthquake Notification Service. After registration you will see a world map on the profile page. Select the custom area on the map for which you want to get notified.

By default all new accounts are set to receive notifications about earthquakes with magnitude 6.0 or higher. However you can customize this and can add multiple recipient addresses.