17 April 2012, At Sea.

As soon as we turned the corner to a more south easterly heading, the wind fell away completely and it turned into a hot and hazy day. The ships speed of 18 knots caused a gentle breeze on the deck and made it very pleasant to be outside. As long as you were careful with your sun block; as you tend to forget how hot the sun is burning down when there is a breeze.  Not only down, but also reflecting off the white superstructure of the ship. Our visibility was no more than 11 miles and that made is impossible to see the shore line.  Which is a pity as it is always nice to see the resorts of Zihuatenego and Acapulco coming by. Even if we cannot call there at the moment, it would at least be nice to see something.  But the lack of wind prohibited that and thus we had to be happy with the wild life and the occasional tanker coming by.  This is the regular shipping route between the port of Salina Cruz, just to the south of Hualtalco and all the Mexican ports further to the north and that means we pass them on a regular basis.

Today we are sailing almost above the Middle American Trench. Southbound our courses remain a bit closer to the land, so the depth of the water is only 3,000 feet but on the return journey when we are heading directly for Cabo San Lucas our route takes us further offshore and then we are right on top of it, resulting in depths of over 18,000 feet. This gully, as I call it, in the ocean floor is caused by one of the smaller tectonic plates that carry the world’s continents. Discovered in the 19th century, by a German scientist called Wegener; it finally gave an answer to the question, why does the earth move (earthquakes) and do we have volcanos in certain places and why not in other places. 

Here at this location the Cocos plate (Do not ask me who dreamt up that name) goes under the Caribbean plate which in its turn is wedged by the North American Plate.  The Eastern edge of the plate slopes down and where the two plates meet we find this deep gully. According to the statistics it has a length of 1,700 miles and a maximum depth of 21,880 feet (6,699 meters) which makes it the 18^th deepest trench in the World. This is of course subject to finding another, deeper trench.  That is very well possible as at the moment we know less about what is under water on earth, than what we know about the surface of the moon.

The trench is at least 4,400 meters deep in all places except at Manzanillo where it (roughly starts) and at Zihuantenego , where it briefly becomes “very shallow” with depths less than 3,000 meters as there is a sort of mountain ridge at the bottom. It is all relative of course, calling 3,000 meters shallow compared to 6,000 meters. But we do the same nearer to the surface. We call 50 feet shallow, if the average depth in the area is 200 feet etc.  

 Hopefully one day, technology will be so good that we can explore vast swaths of the ocean and are not limited to very small areas with specialized submarines that can withstand the pressure. I read recently that James Cameron (of Titanic and Avatar movie fame) went all the way down in the Mariana trench, which is the deepest on earth and maybe that sort of publicity will result in more funding for ocean floor exploration.

At the moment this area is fairly quiet and stable. The last major earthquakes were in the 80’s and also the volcanic eruptions are not spectacular.  I reported recently that we had an earthquake more inland in Mexico but that affected the area near Mexico City; the coastal areas were not affected.  Still if it has been quiet for awhile then we can expect something to happen in the near future. Although the plates move slowly, they do move and do not stop. At a certain moment the pressure becomes too much e.g. one plate cannot stop the other from moving and then with a shudder it slides a little under the upper plate.  If it happens while we are at sea, we have nothing to worry about. If it happens in port, hopefully I would be able to get out to open waters, in case it triggers a tsunami.

Tomorrow we are in Huatalco de Santa Cruz and with a wind still day expected.  That will mean that it is going to be a very warm day. The temperature might top the 90o degrees Fahrenheit (31oC). Hopefully all the guests will have listened to my noon time speech, where apart from being urged to wash your hands to stay healthy, also sun block, water and a hat, figured prominently.