METOC EFFECTS ON VARIOUS WARFARE OPERATIONS LEARNING   OBJECTIVES:   Identify  the publication   that   outlines   the   contents   of antisubmarine  (ASW),  space  and  electronic warfare   (SEW),   strike   warfare   (STW), antisurface   warfare   (ASUW),   and   antiair warfare  (AAW)  briefs. It is beyond the scope of this text to discuss all the information  considered  important  for  the  various  METOC briefs  listed  below.  Significant  information  regarding these briefs, for the most part, is confidential. Refer to the text Environmental Effects on Weapon Systems and Naval Warfare, (S)RP1, for a discussion of these topics: l Environmental factors affecting ASW operations .  Environmental  effects  on  special  warfare l Environmental effects on SEW . Environmental effects on chemical, biological, and  radiological  (CBR)  operations .   Environmental   considerations   for   STW operations l   Environmental   considerations   for   ASUW operations l   Environmental   considerations   for   AAW operations l  Target  environmental  conditions Now let’s discuss those elements of importance during  the  planning  and  execution  of  minewarfare (MIW)  operations. BRIEFING OF METOC EFFECTS ON MIW  OPERATIONS LEARNING OBJECTIVES: Brief the effects that  water  depth,  currents,  tides,  and  bottom characteristics   have   on   MIW   operations. Understand   the   impact   of   the   magnetic, acoustic,  pressure,  and  biological  environments on  MIW  operations. There are environmental considerations unique to the planning of MIW operations and this section will be devoted to this topic. For further discussion of MIW operations, refer to the technical manual, Composite Warfare  Oceanographic  Support  Modules  (CWOSM), Part 1, TM  04-92. WATER DEPTH Water depth is a factor to be considered in the spacing of mines, sensitivity setting, mine type, and mine impact velocity (air-laid mines). .  Bottom  mines  —  In  deep  water  (180  ft  or greater), detonation will not cause much of a disturbance in the upper layers of the ocean. . Moored mines — Depth may exceed the mooring range required for the mine to be effective. l Sensitivity and actuation width — Important for bottom mines since an increase in depth will result in a decrease of the sensitivity and actuation width of a bottom  mine. .  Damage  width  —  Water  depth  affects  the damage width in the same way as in actuation width. Increasing water depth causes a reduction in the damage width of a mine. l Mine burial upon impact — The depth at which terminal  velocity  is  reached  depends  on  the  initial velocity when launched and the depth of the water. CURRENTS Subsurface currents may  set in  different  direction as mines descend, and current velocity may also vary during   descent. These  factors  must  be  considered during planning of MIW operations. l Burial — Burial on the sea floor can result from scour (water velocity increases around the mine, setting sand and sediments in motion, burying the mine). Once the mine is completely buried, scouring stops. . Sand ridge migration —  Currents  may  cause large sand dunes to migrate along the bottom in the direction of the current. The dunes can be as high as 12 to 20 ft. . Mine dip (vertical movement of mines) — An increase in mine depth from the normal vertical position above the mooring point. Current action creates forces against the mine, increasing the depth, Dip is directly proportional  to  current  speed;  therefore,  dip  will increase with faster currents. During  flood and ebb 13-4