Japan mistakenly issues magnitude 9.9 earthquake alert, withdraws it within minutes. The Japan Meteorological Agency (JMA) on Friday mistakenly issued an emergency earthquake warning predicting a massive magnitude 9.9 tremor, triggering alarm across parts of the country before withdrawing the alert eight minutes later. The warning had forecast strong shaking across northern, eastern and central Japan. This comes as a magnitude 6.9 earthquake struck Russia on Friday.