Profile of Lake Toba
Lake Toba is made up of four overlapping volcanic craters that adjoin the Sumatran volcanic front. The youngest one is the world’s largest Quaternary caldera, with a length of 86.15 kilometers (53 mi) and a width of 30 kilometers (18.6 mi), intersecting the other three. Below is a summary of the lake’s geological profile.
| NAME | Lake Toba (Danau Toba) |
| COUNTRY | Indonesia |
| SURFACE AREA | 1,130 km2 (436 sq mi) |
| MAXIMUM DEPTH | 529 m (1,736 ft) |
| AVERAGE DEPTH | 213 m (699 ft) |
| LAKE TYPE | Volcanic |
| LENGTH | 86.15 km (53 mi) |
| WIDTH | 30 km (18.6 mi) |
| CATCHMENT AREA | 3,726 km2 (1,439 sq mi) |
| ALTITUDE | 900 m (2,953 ft) |
| VOLUME | 240 km3 (57.6 cu mi) |
| OUTFLOWS | Asahan River |
| ISLANDS | Samosir |
| SHORE LENGTH | 464 km (288 mi) |
| AGE | 10,000 – 100,000 years |
| MIXING TYPE | Homogeneous |
| FROZEN | Never freezes |
| RESIDENCE TIME | 20,777 days |
| FISH SPECIES | Catfish, tilapia |
| TROPHIC STATE | Oligotrophic (nutrient-poor) |
| ORIGIN | Volcanic |
| AVERAGE DISCHARGE | 134 m3 / sec. |
Source: Lakepedia.com
See also History of Lake Toba.