Telecommunications cable in the context of "Communication channel"

A stamukha (plural: stamukhi; from Russian стамуха) is a grounded accumulation of sea ice rubble that typically develops along the boundary between fast ice and the drifting pack ice, or becomes incorporated into the fast ice.- see also NSIDC. It is a pressure ridge. Wind, currents and tides contribute to this phenomenon. Stamukhi tend to occur in belts that are parallel to the shoreline, along coastal shoals, at water depths of about 20 m (65 ft), but that can reach 50 m (160 ft). They can build up to heights 10 metres (33 ft) or more above the waterline. Although they remain pinned to the seabed, these features can be subject to small displacements, either due to thermal expansion or to the pressure exerted by the drifting pack ice onto the fast ice. Because stamukhi tend to be deeply grounded, they may occur as isolated ice features in the open sea during the summer season, after the surrounding ice has melted away.

Since stamukhi extend downward into the seabed, they present a risk to submarine pipelines and telecommunications cables that cross the shoreline. Seabed penetration by the ice can reach a depth of 5 metres (16 ft).

Directional boring, also referred to as horizontal directional drilling (HDD), is a minimal impact trenchless method of installing underground utilities such as pipe, conduit, or cables in a relatively shallow arc or radius along a prescribed underground path using a surface-launched drilling rig. Directional boring offers significant environmental advantages over traditional cut and cover pipeline/utility installations. The technique is routinely used when conventional trenching or excavating is not practical or when minimal surface disturbance is required.

Although often used interchangeably, the terms directional boring and horizontal directional drilling are distinct in that they convey a different sense of scale. The term "directional boring" or "bore" is generally reserved for mini/small sized drilling rigs, small diameter bores, and crossing lengths in terms of hundreds of feet. Generally, the term Horizontal Directional Drilling (HDD) is intended to describe large/maxi sized drilling rigs, large diameter bores, and crossing lengths in terms of thousands of feet. Directional boring and HDD are similar in some respects to directional drilling associated with the oil industry, however, an equal comparison cannot be drawn as the procedures serve markedly different functions. Directional boring can be utilized with various pipe materials such as PVC, polyethylene, polypropylene, ductile iron, and steel provided that the pipe's properties (wall thickness and material strength) enable it to be both installed and operated (if applicable) under acceptable stress limits.