Japan’s Meteorological Agency (JMA) issued an erroneous earthquake early warning Friday that estimated a magnitude 9.9 quake and predicted strong shaking across northern and central Japan, including the Tokyo region. The alert was issued at approximately 12:36 p.m. local time and canceled at 12:48 p.m., according to Japanese public broadcaster NHK.

The warning identified the earthquake’s location as the Kuril Islands region and initially estimated its magnitude at 9.9, with a depth of 140 kilometers, or approximately 87 miles. However, the actual earthquake was substantially weaker and occurred near Russia’s Kamchatka Peninsula.

The U.S. Geological Survey (USGS) measured the earthquake at magnitude 6.9, placing its epicenter approximately 76 kilometers, or 47 miles, northeast of Ozernovskiy, Russia. Its estimated depth was 143.2 kilometers, or about 89 miles.

According to NHK, the earthquake did not produce shaking in Japan, and authorities issued no tsunami warnings. The JMA said it would investigate what caused the major error in its early-warning system.

The mistake is particularly significant because a magnitude 9.9 earthquake would exceed the strongest earthquake ever recorded. According to the USGS, the largest recorded earthquake was a magnitude 9.5 event that struck Chile in 1960.

The difference between the erroneous estimate and the actual earthquake is enormous. A magnitude 9.9 quake would release roughly 32,000 times as much energy as a magnitude 6.9 earthquake, underscoring the scale of the agency’s miscalculation.

Japan is highly vulnerable to major earthquakes and relies on early-warning systems to give residents and emergency services advance notice of potentially dangerous shaking. Although the alert was canceled without reported shaking or tsunami warnings in Japan, the agency’s investigation will seek to determine why its system generated such an extreme estimate.