A 7.4 magnitude aftershock hit just off the coast of Japan at 11:30 PM JST (1430 UTC) on Thursday, April 7. The epicenter of this earthquake is just 73 miles from the nuclear plant at Fukushima and 41 miles from the epicenter of last month’s 9.0 earthquake. As such, Japan’s meteorological agency issued, and then lifted, a tsunami warning for a wave of up to 6 feet for the coastal area that has been already torn apart by the March 11 earthquake and tsunami. These events are believed to have killed some 25,000 people and have sparked an ongoing crisis at the nuclear power plant. That tsunami was estimated to be higher than 120 feet. The ARRL asks that you keep 7.030 MHz clear for emergency use. In addition, these frequencies should also be kept clear: 3.525, 7.030, 7.077, 7.087, 7.097, 14.100, 21.200 and 28.200 MHz.
Source:http://www.arrl.org/news/