[Updates in progress!]
In the previous earthquake, KDDI and NTT DoCoMo mobile phone communications were used to regulate part of the Tohoku and Kanto regions, these mobile phone lines are currently busy now. The two companies are requesting that subscribers refrain from non-essential calls and e-mail.
Here are some important links:
BT Earthquake Resources: http://www.blacktokyo.com/emergency/
BT Twitter: https://twitter.com/blacktokyo
NHK World Live News in English: http://disasterjapan.wordpress.com/
Earthquake and Weather Tracking: http://earthquake.usgs.gov/earthquakes/world/index.php?region=Japan
Please remember in the 3/11 earthquake the first tsunami was only two-meters. Many returned to their homes. Afterwards, the bigger tsunami hit!