Shiveluch (Kamchatka): Explosive activity continues. Volcanic Ash Advisory Center (VAAC) Tokyo warned about a volcanic ash plume that rose up to estimated 13000 ft (4000 m) altitude or flight level 130 and is moving at 25 kts in E direction. The full report is as follows: VA EMISSIONS CONTINUING OBS VA DTG:20/1720Z to 13000 ft (4000 m) …20 Apr: Volcanic Ash Advisory Center Tokyo (VAAC) issued…