Orphan Knoll Dive 3 : 1978 Dredge Location / NE Mound Field

Around forty years ago, mounds on the NE corner of Orphan Knoll were discovered. The theories as to what the mounds were comprised of are various (authigenic carbonate, hydro-thermal activity, up-turned blocks, etc.) but unconfirmed. Dive 3 on Orphan Knoll will hopefully help clear-up the mystery of the mound composition.

The mound field on the NE corner of The Knoll were taken in 1979 and 1980. The data loosely visualizes the surface of The Knoll with a visible swath of ~50 Km. The low resolution black and white imagery, historic depth measurements and 12 KHz and 3.5 KHz seismic profiles are all the data that has been used to identify these mounds. There are roughly 250 mounds, whereby the geological origin remains unknown..........until now.

A hard Scleractinian coral, Desmophyllum dianthus, was found in 1978 by the Geological Society of Canada (GSC), lead by Dr. C. Keen. The fossilized and alive coral suggests that these mounds could be adequate substrate for deep-sea coral growth.

Determining the marine biology of these mounds and the geological composition of these mounds will hopefully end the debate on the origin of these mysterious mounds.

The dive plan attempts to traverse 3 mounds where the 1978 dredge locations were taken.

del.icio.us Tags: Orphan Knoll,Cold-water Coral and Sponge,Mounds

Orphan Knoll Dive 2 : Summary

Unexpected Marine Geology! Big Vase-like sponges and Black Corals! What an unexpected dive!
Geologically, the initial view was of a limestone-like bedrock with possibly Manganese nodules scattered on the sea floor. The mounds on the SE ridge of Orphan Knoll appear to be a series of volcanic mounds.

Some unrecognizable species of sponge and some unconfirmed Black Corals (Antipatharian) were some of the major biological highlights of these SE mounds (shown above).

The dive finished with a high-resolution IMAGINEX multibeam transect over top of the second mound.

The next dive, Dive 3, is a DFO mooring recovering dive with the chance to see what is living at the top of the south Orphan Knoll canyon feature.

del.icio.us Tags: Manganese Nodules,Basalt,SE Orphan Knoll,Antipatharia,Deep-Sea Sponges

Orphan Knoll Dive 1 : Orphan Seamount

The Orphan Seamount, found 620 Km east of St. John’s, NL, is a 2000m tall submarine feature that starts at a depth of 4500m.

Even though the Orphan Seamount has never been explored or studied, the shape and relation to Orphan Knoll suggests that it is probably a volcanic seamount.

In 2001 the USCG Healy collected high resolution multibeam imagery of the Orphan seamount and the SE ridge of the Orphan Knoll.

The CCGS Hudson and CSSF ROPOS are being used to collect biological, geological and seismic data on the Orphan seamount.

The dive plan for the Orphan Seamount will start on the NE side of the seamount and finish on the top of the seamount. The dive site and the dive plan is shown in the images below.

Seamounts near Newfoundland and Labrador have not been studied with the aid of remotely-operated vehicles (ROVs) before. The CSSF ROPOS is an ROV that can reach depths of ~5000m below sea level. The current floatation package installed allows ROPOS pilots to dive 3000m below sea level.

Seamount’s in other areas of the world have shown to be hotspots of biodiversity for many different types of invertebrates, including cold-water corals and sponges.

These invertebrates are living on unique and sometimes hostile substrate (e.g. hydro-thermal vents, black smokers, etc.).

The geological constitution and origin of this seamount coupled with unknown deep-sea biological fauna make exploring the Orphan Seamount an exciting adventure!