Numazawa (volcano)

Numazawa is a stratovolcano located in Fukushima Prefecture, Japan. It is part of the Bandai-Asahi National Park and is characterized by a large caldera lake, also called Lake Numazawa, which occupies the caldera formed by a major eruption approximately 6,000 years ago.

Geological Characteristics:

The volcano is primarily composed of andesite and dacite lavas and pyroclastic flows. Post-caldera activity has been relatively minor, consisting mainly of fumarolic activity and hot spring formation around the lake shore. The lake is known for its distinctive emerald green color, which is attributed to the presence of colloidal sulfur derived from volcanic activity.

Eruptive History:

The most significant eruption in Numazawa's history was the caldera-forming event around 6,000 years ago. This eruption resulted in the formation of the present-day caldera and the deposition of extensive pyroclastic deposits. Subsequent eruptions have been smaller in scale and localized within the caldera.

Current Status:

Numazawa is currently considered an active volcano, although its activity is relatively low. Monitoring is conducted by the Japan Meteorological Agency (JMA) to track any changes in volcanic activity, such as ground deformation, seismicity, and gas emissions.

Tourism and Recreation:

Lake Numazawa and the surrounding area are popular destinations for tourism and recreation. Activities include hiking, camping, fishing, and boating on the lake. The area offers scenic views and opportunities to experience the natural beauty of the volcanic landscape. The hot springs around the lake also attract visitors seeking relaxation and therapeutic benefits.