Glacial Erratic in Puget Sound

February 26, 2016


Photographer: Rebecca Roush
Summary Author: Rebecca Roush
Four Mile Rock at right center is a glacial erratic in Seattle, Washington. The rock owes its name to its distance from an early Seattle landmark known as Yesler's Wharf that was exactly four nautical miles away. This granitic erratic is approximately 20 ft (6 m) high and about 120 ft (36.5 m) from shore. It’s fully accessible during low tide; however, even at high tide it protrudes well above the water line and is hence a potential hazard to navigation. Four Mile Rock came to its present location in Puget Sound as a result of glacial surging during a previous ice age. The snow-covered Olympic Mountains are visible in the background. Photo taken on February 7, 2016.
Photo Details:Camera Maker: HTC; Camera Model: 0PJA2; Focal Length: 4.73mm (35mm equivalent: 5mm); Aperture: ƒ/2.2; Exposure Time: 0.0010 s (1/985); ISO equiv: 50.