Memorial Park of the Houses Destroyed by Debris Flow
This memorial park, which brings you face-to-face with the destructive power of the peninsula’s volcanoes, serves as an important place of remembrance for the people of Shimabara.
On November 17, 1990, almost 200 years after a catastrophic eruption leveled Shimabara and forever changed its landscape, Mt. Fugen (1,359 m) awoke once more. The eruption began with a swarm of earthquakes beneath Tachibana Bay. In the months and years that followed, the mountain erupted multiple times, releasing lava, ash clouds, and—its greatest hazard—pyroclastic flow. The danger would not end until 1995, when the new peak, Mt. Heisei Shinzan (1,486 m), finally settled.
Pyroclastic flow refers to a mixture of hot gases, ash, and volcanic rock that is sometimes created when a volcano erupts. The particles of rock and ash form a cloud on top of a thin layer of superheated gas that reduces friction with the ground and causes the mixture to behave almost like a liquid. As a result, pyroclastic flow can come billowing down an erupting mountain at tremendous speeds. Although many assume that the destructive power of volcanoes comes from lava, pyroclastic flow can be even more dangerous.
Some of the farthest-reaching damage to the town occurred on August 8 and 14, 1992, when heavy rainfall washed debris down the east side of Mt. Fugen and completely filled the usually dry Mizunashi riverbed. Once the mud flow, called a lahar, reached the seashore, it began to back up into the river, eventually breaching the riverbank and completely burying many houses.
This park stands on several meters of debris. There are 11 houses preserved and exhibited here; the three under the tent were moved here to protect them from the elements and to better display the damage caused by the lahar. Luckily, the houses had already been evacuated when the flow hit.
In the decades since the 1990–1995 eruption, Shimabara has recovered. Barriers have been constructed up and down the Mizunashi River to control and direct future pyroclastic flows, protecting the city from future eruptions.