Monterey Submarine Canyon

Monterey Canyon is the largest submarine canyon on the West Coast of the Americas and its gorge, though not as long, is comparable to that of the Grand Canyon of the Colorado.

The canyon begins about 1 kilometer (0.6 mile) offshore and extends in a winding course seaward for over 160 kilometers (100 miles). It has two main tributaries, Soquel Canyon from the north and Carmel Submarine Canyon from the south, which join the main canyon at depths of around 600 meters (2,000 feet) and 2,000 - 2,040 meters (6,600 - 6,700 feet) respectively.

At a depth of about 120 meters (400 feet) several sand chutes merge to form this sizeable canyon. In its upper reaches the canyon forms a U-shaped gorge some 80 kilometers (50 miles) long. At about 2,750 meters (9,000 feet) the canyon loses its U-shaped characteristics and runs into a sea-floor trough which continues to a depth of about 3,650 meters (12,000 feet). The trough terminates in the Monterey deep-sea fan; the volume of this submarine delta is estimated to be nearly 100 times greater than the volume of material that the canyon itself displaced, indicating that the canyon is an ancient one. It may date to the Miocene.

Dredgings on the canyon walls have yielded Pliocene rock overlying what is probably Miocene rock and earlier granite. The bottom of the canyon may be a granite gorge similar to that at the head of the Carmel Canyon. In the Plio-Pleistocene, the Pajaro River may have been the cutting agent (see Pajaro Gap).

Integrity: Pristine Use: Research

Ref: Martin, Bruce and K. 0. Emery, 1967. Geology of Monterey Canyon, Calif. Amer. Assn. Petro. Geol. Vol. 51:11

January 1978