The Lake Bosumtwi impact crater is 10.5 km (6.5 mi) in diameter, slightly larger than the present lake which is approximately 8 km (5.0 mi) across, and is estimated to be 1.07 million years old (Pleistocene period).[1][9] There is a highly speculative theory that connects this event to the short-term Jaramillo geomagnetic reversal.[10]