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Saturday, February 26, 2022

Wednesday, February 23, 2022

Milwaukee Deep and Deep Diving Animals

     The deepest part of the Atlantic Ocean is not where you would probably think it is. It's not in the middle of the Atlantic somewhere. The Milwaukee Deep, also known as the Milwaukee Depth, is part of the Puerto Rico Trench. 
     Together with the surrounding area, known as Brownson Deep, the Milwaukee Deep forms an elongated depression that constitutes the floor of the trench. The floor of the trench constitutes the deepest point in the Atlantic Ocean. 
     It is named for the USS Milwaukee, US Navy light cruiser (the third of five Navy ships with that name) which was itself named for the city of Milwaukee. While steaming north of Hispaniola and Puerto Rico on February 14, 1939, Milwaukee discovered the deepest place in the Atlantic Ocean. The spot is now known as the Milwaukee Deep. 
     The Milwaukee's depth reading was 28,680 feet, but on August 19, 1952, a US.Fish and Wildlife vessel obtained a reading of 28,560 feet. One of the area's earliest soundings was obtained June 12, 1852 by Lieutenant S. P. Lee with a reading of 22,950 feet. 
     In 1964, a French submersible explored the Puerto Rico Trench to a depth of approximately 27,200 ft but did not reach its deepest point. On December 21, 2018 Victor Vescovo made the first manned descent to the deepest point of the trench and measured a depth of 27,480 feet. 
     The Deep itself is a spot 100 miles northwest off the coast of Puerto Rico and is a low spot where two tectonic plates meet along the boundary between the Caribbean Sea and the Atlantic Ocean. 
 

     The suspense of what's down there is probably killing you, so just what IS down there? The bottom is covered with mud, sand, rock and shells. But, the Deep is also home to a host to several new species discoveries, like the sei, fin, and minke whales; it is also the well-known humpback whales' breeding ground.
     Speaking of whales, how do sea creatures survive at great depths, far beyond what man can survive? The physiological challenges in adapting to pressure faced by creatures that routinely travel from the surface to great depths is nothing short of amazing. 
     The sperm whale and the bottlenose whale are known as exceptional divers. Dating back to whaling days they have been known to have made dives lasting as long as two hours after they were harpooned. Today, sonar tracking and attached recorders reveals them making dives as deep as 6,000 feet although routine dive depths are usually in the 1,500- to 3,000-foot range, and dives can last between 20 minutes and an hour. 
     Diving to those depths can result in distortion and tissue compression, especially in gas-filled spaces in the body such as the middle ear, sinuses in the head and the lungs. In human beings these distortions are known as the squeeze.
     In some species of whales, dolphins and porpoises, the middle ear cavity is lined with an extensive blood vessels which it is believed become engorged at depth and thus reduce or eliminate the air space. 
     These animals also have large Eustachian tubes between their ears and the large sinuses of the head. These sinuses also have a lot of blood vessels which are thought to function in a similar manner. 
     Another organ susceptible to compression are the lungs. In deep-diving whales and seals, the peripheral airways are reinforced and it is believed this allows the lungs to collapse during deep dives. 
     Collapse of the lungs forces air away from the alveoli, where gas exchange between the lungs and blood occurs. This is important in deep dives because it prevents the absorption of nitrogen into the blood. In humans high blood nitrogen pressure can exert a narcotic effect (so-called nitrogen narcosis) on the diver. It may also lead to nitrogen bubble formation during ascent which is known as decompression sickness or the bends. 
     Collapse of the lungs in deep diving animals avoids these two problems. In animals making deep dives the lungs cannot serve as a source of oxygen during the dive. Instead deep-diving whales and seals rely on large oxygen stores in their blood and muscle. 
     First, these animals have mass specific blood volumes that are three to four times those found in land mammals. Second, the concentration of hemoglobin (the blood's oxygen-transporter) is also elevated to a level about twice that found in humans. Third, the concentration of the oxygen storage protein in muscles (myoglobin) is about 10 times that in human muscle. 
     So, deep-diving mammals such as the sperm whale have air cavities that are lined with blood vessels which are thought to fill at depth, obliterate the air space, and prevent the squeeze. 
    The lungs collapse, which prevents lung rupture and blocks gas exchange in the lungs. Lack of nitrogen absorption at depth prevents the development of nitrogen narcosis and decompression sickness. 
     In addition, because the lungs do not serve as a source of oxygen at depth, deep divers rely on enhanced oxygen stores in their blood and muscles.

Saturday, February 19, 2022

Homemade De-Icer

     With freezing rain on driveways, sidewalks and steps the best way to melt the ice is, of course, salt, but it's very bad for concrete. Another option sometimes mentioned is lawn fertilizer, but while it does successfully melt the ice under and around the pellets, it can stain some concrete. 
     A third option that works is hot water, rubbing alcohol and dishwashing liquid. To make the solution, combine 
 
* 1/2 gallon of warm water
* six drops of dish soap
* 1/4 cup rubbing alcohol 
 
in a large container. 
     Then pour the solution on the icy area that you want to melt. Note: At some point it will refreeze. 
     According to home improvement expert Bob Vila, rubbing alcohol has a lower freezing point than water, so it speeds up the melting process. He also suggested keeping a mixture of rubbing alcohol and water (no soap) in a spray bottle in your car in order to quickly melt ice on a car door that’s frozen shut or a frosted windshield. If at home, DO NOT USE HOT WATER!! It can cause a cold windshield to break!

Tuesday, February 1, 2022

The Boatswain's Pipe

     Everybody who has ever been aboard a U.S. Navy ship (at least in the old days before all the electronic gadgetry) has heard the shrill call of the Boatswain's Pipe. 
     For those unfamiliar with U.S. Navy ratings, the Boatswain Mate is the oldest rate in the Navy. They supervise the maintenance of the ship inside and out, in addition to a diverse roster of other responsibilities: Standing watch as lookout or Boatswain Mate of the Watch. Repairing, maintaining and stowing equipment. Training, directing and supervising ship's maintenance personnel. To name a few of their duties.
     The pipe itself is narrow tube which directs air over a metal sphere with a hole in the top. The Boatswains Mate opens and closes his hand over the hole to change the pitch. The rest of the pipe consists of a flat piece of metal beneath the tube and a key ring that connects a long silver or brass chain that goes around the neck. 
     Historically the boatswain's call was used to pass commands to the crew when the voice could not be heard over the sounds of the sea. Because of its high pitch, it could be heard over the activities of the crew and bad weather. 
     In the days I was aboard ship it was used over the ship's 1MC (loudspeaker) before announcements were made. It was also used to announce that flag-rank officers or an important guest was boarding or departing a Navy ship. Additionally, it is used in other ceremonies. 
 
You can listen to Boatswain's (and bugle) calls HERE.