The message ran for about 15 seconds on the network, which broadcasts to a service area of about 70,000 homes.
Network officials said an operator mistakenly added the message to another one about a large-scale rain warning issued in connection with the approaching Typhoon Ma-On.
Tokai earthquakes are the names given to large scale earthquakes that strike the Tokai region southwest of Tokyo every 100 to 150 years. The last major Tokai earthquake struck in 1854, so the region is due to be hit. Government earthquake prediction places considerable emphasis on guessing when a Tokai earthquake will hit.
Network officials said the mistaken broadcast occurred just after midnight on July 19. A message appeared on screen, reading “The Meteorological Agency has announced information about a Tokai earthquake. It is looking into whether this is related to an envisioned Tokai earthquake.”
The network broadcast an on-screen apology from the afternoon of July 19 onward, and apologized to viewers in a news program that aired from 6 p.m. on the same day.