West Hawk Lake is located on the Southeast corner of the province of Manitoba at a latitude of 49º 46'N and a longitude of 95º 11'W. It is 100 million +/- years of age and is approximately 3.6km in diameter. It has a central depth of approximately 111 metres. Unlike many Canadian impact features this Crater Lake is easy to reach. West Hawk Lake is located a mere 2km north of the Trans Canada Highway and 4km west of the Manitoba-Ontario border. Interest in West Hawk Lake was initiated because of its great depth in comparison to surrounding lakes in the area (Falcon Lake 21m and Caddy Lake 5.8m) and because of its circular shape. A gravity survey showed an anomaly indicating the rock beneath the lake had been severely fractured, as in other known meteorite craters.
From January to March 1965 Canadian astronomers Halliday and Griffen supervised the drilling of a test hole at the centre of the lake. The hole reached a depth of 727m below the lake level. The bottom of the lake was found at 108m and soft sediment encountered to a depth of 151m. Boulders were then encountered for the next 3.3m which made drilling difficult.
The transition from sediments to fragmented rock occurs at the 202m mark. Study of the fragments near the 457m mark show micro fractures in the quartz crystals, similar to that of the Barringer crater in Arizona and other impact craters.
Early in 1966 Halliday and Griffen returned to West Hawk Lake and supervised the drilling of three more holes. From this date the best estimate for the original rim diameter of the crater is 2.4km. This indicates that severe erosion has moved the present shoreline about 600m beyond the pear of the original rim which may well have stood 100m above the present lake level.
Reasonable estimates suggest the crater was formed by a meteorite 150m in diameter impacting the Earth at 16km/sec (58000km/hr or 36000miles/hr).
Think of it! This meteorite was about the size of two football field's (150m) and it blew a hole almost 2km in diameter. A 32 story building such as the Richardson Building could be placed in the centre of the lake and it would barely break the lake's surface. Similarly, the top of the "Golden Boy's torch on top of Manitoba's Legislative Building would be 34m (109ft.) below the lake's surface. ( For purposes of conversion: 1metre is equal to 3.28 feet.
Researched by Robert Harbottle