The gigantic Meiwa Tsunami which brought serious damage to the Miyako-jima and Yaeyama Islands started as the eruption of an undersea volcano, causing an earthquake in the southeastern area of the seas off Ishigaki-jima Island in April of 1771. The tsunami hit the seashore of southeastern of Ishigaki-jima Island. The initial part of tidal wave peaked at a spot 84.5 meters above sea level. Damage amounted to the destruction of 2,176 houses and 2,223 rice bales were flushed away. Deaths amounted to 9,313 people; one third of Yaeyama's total population was lost. After the tsunami, other natural disasters and epidemics broke out. It was said that the spread of epidemic was mostly a man-made disaster. When post-tsunami epidemics broke in the same year as the Meiwa tsunami in the southern part of mainland Okinawa, grain was provided to those afflicted. However, in the case of the Yaeyama tsunami, people were not provided with any food and damage grew even greater than before because of deaths by starvation. In addition, the government levied the amount of the per capita tax on those dead who had not paid. It meant that people who survived were coerced into forced labor to redeem their debt. The population of Yaeyama continued to decrease because of other natural disasters, epidemics and taxation. It had decreased to one third of the population before the tsunami in the latter part of the Ryukyu Kingdom.
The tsunami brought severe damage to Miyakojima-island as well. It is written in Miyako historical records that 2,548 people died. The tsunami surged up to 30 meters above sea level.