Akanuma (Copper Pond)
Akanuma (Copper Pond) is a rust-hued, horseshoe-shaped crater pond, created during the eruption and partial collapse of Mt. Bandai in 1888. It lies in a forested caldera on the northern flanks of the now inactive volcano.
High levels of iron hydroxide in the lake give the pond its coppery red color. The acidity levels are too high to support aquatic life. Fumaroles, openings in the side of Mt. Bandai visible from the pond, emit gases.
Akanuma (Copper Pond) has an elevation of over 1,000 meters above sea level. Geologists believe its water seeps downward through the earth and emerges at lower altitudes as springs that run into the colorful Goshikinuma cluster of ponds some 300 meters below, one of which is similarly named Akanuma (Red Pond). Minerals enter the lakes in varying quantities, altering the color, acidity, and ecosystem of each pond. When Akanuma (Copper Pond) freezes over, you can hire a guide to show you a safe route to its “Yellow Falls,” a frozen waterfall with a golden, sulfur color.