- Altitude: 158 m above sea level
- Surface Area: 542 sq km
- Maximum Depth: 280 m (maximum recorded)
- Shoreline Length: 185 km
Lake Hazen, located at the northern end of Ellesmere Island, is the world's largest lake entirely north of the Arctic Circle. Melting valley glaciers in the Grant Land Mountains supply water to the lake during the summer and Ruggles River flows out of it. Most years the lake remains frozen during the summer and therefore is it usually monomictic. The Hazen Fault Zone, just north of the lake, receives intense solar radiation and the lake enhances this effect so the area around Lake Hazen is a thermal oasis in an otherwise polar desert. Only 25 mm of precipitation falls in the region annually. The arctic char is the only species of fish present in the lake and is possibly the most northerly stock of this fish in the world.
Lake Hazen is located on the Hazen Plateau of the Eureka Uplands, which is characterized by Palaeozoic rocks. Just north of the lake is the Hazen Fault Zone, which forms the boundaries of the ice-covered Grant Land Mountains.