Finding the deepest point on the planet has been man’s dream ever since prehistoric times. Finding the lowest ground also meant getting closer to the center of the planet. Hence, a British ship “HMS Challenger” went on an expedition in the early 1800’s to map out all the oceans on the planet for their depth. In four years, the ship traveled as much as seventy thousand kilometers, “a quarter of the journey to the moon”. Some area in the western Pacific were recorded to be “4075 fathoms” or about 5 miles deep using an anchored rope for measurement. Some seventy-five years later, sonar technology came into existence to map out submarines. Hence, a research vessel set out on the same journey as Challenger to find the lowest point using sonar. They found a point in the western Pacific some seven miles deep and hence that point came to be known as “Challenger Deep” after the research vessel. This part of the ocean existed as a trench “some thirty times deeper than the empire state building is high”. Hence, it became to be known as “Mariana’s Trench” after the actual journey taken by “Triesk” a research vessel that ventured into the trench in 1953. With the increasing earthquakes and tsunamis in the 1900’s as well as the twenty-first century, the expeditions to the trench raised a “sixty thousand dollar” question. Is Mariana’s Trench a cause of Earthquakes and tsunamis? Science and scientists, geologists and oceanographers; all have tried to put the collected evidence together to come up with a hypothesis!
The evidence to find the answer to the “sixty thousand dollars” question starts off with the expedition by the “Tries k”. The expedition into the trench pointed out some wrong assumptions about the ocean floor being a lifeless area. The pilot of the “Triesk” pointed out that even with the high pressure in the water above the trench surface some seven miles deep, they found a foot long flat fish. With pressure assumed to be some 16000 psi, the finding of life on the trench’s ocean floor itself raises a question about the environment of the trench and the geological features. Later in time, when all the earth’s ocean were mapped out with sonar data, they found a network of mountain and trenches, the largest geological feature on the planet. It was pointed out that the movements of similar mountain and trenches caused earthquakes in a phenomenon called “Plate Tectonics”. These plates or layers of earth’s crust move and grind as a result of flowing magma underneath causing Earthquakes. Then, the magnetic anomaly detector picked up magnetic rocks parallel to the ridges formed by minerals in the magma. These “Zebra striped” features pointed out in geological maps are thought to be the cause of Earth’s magnetic poles. Poles that reverse every thousand of years as magma is pushed up and old crust away from the surface during plate tectonics. Next, an expedition to find magma underneath the ocean picked up hydrothermal vents that warm up the ocean. This and other observations led to the development of “Subduction theory”. During plate tectonics, heavy plates in the eastern Pacific get pushed beneath the lighter plates and they take with them sediments and mineral formations for thousands of years. The water that the plates take with them underneath the ocean floor reacts with magma to form volcanoes. Hence, the volcanic islands in the process of “Subduction” – a process powerful enough to create the trench. As the plate goes underneath, it “digs into the mantle” where colliding plates form a trench or a “giant crease in the ocean floor” These subduction zones cause violent earthquakes and tsunamis. And though the trench is the “deepest subduction zone”, it is not thought to be responsible for any earthquakes. The answer comes after core sample is collected from the volcanic hills of Mariana’s trench. The rocks happen to be “serpentine” a weak rock compared to volcanic rocks that grind and cause earthquakes. This mud type rocks can “easily be scratched”. Hence, the lack of friction during subduction and no earthquakes. Furthermore, scientists believe that some millions of years ago, the Pacific plate went underneath the “Philippine plate” and continues to move towards Mariana’s trench – “its graveyard”. This trench also called “the world’s largest recycling plant” devours earth’s crusts as confirmed by data from GPS transmitters on western Pacific islands. Hence the full explanation for the existence of “Mariana’s trench”.
Since the sixty thousand dollar question and the theory behind the “existence of Mariana’s trench” are assumed to be solved through the subduction hypothesis, another question rises to take its place! Will the trench cause earthquakes and tsunamis in the future. Core samples from the trench are hypothesized to be “sixty million years old”. The rocks are also heavier than any other rocks on the ocean floor since “the crusts formed over magma in the western Pacific eventually cooled and became heavier”. This heavy ocean floor which gets heavier in the years to come could possibly replace the mudrock or serpentine rock in the trench eventually causing friction and earthquakes in the future not mentioned in the documentary below.
In terms of economics and material applications, Mariana’s trench along with the research technology involved to find the answer to the “sixty thousand dollar question” creates new possibilities for innovation and product development. Transmitters used on western Pacific could also be placed in the trenches and subduction zones to record underwater activities caused by plate tectonics. These transmitters could also include battery powered seismographs anchored to a floating receptor on the ocean’s surface to record earthquake activity. The receptor could transmit a violent shake in subduction zones to the satellites and finally to earthquake and tsunami warning centers. This method could be faster than observing tsunami waves via satellite or recording earthquake activity via seismographs on land rather than underneath water. With the discovery of new materials such as graphene (100 times stronger and lighter than steel), the transmitters or seismographs could be placed in an enclosed case like an airplane’s black box to withstand the extreme underwater pressure (some “9600 psi” on Mariana’s trench Surface). Furthermore, the same material (Graphene) could be used in cargo containers on container ships. Recovery of containers from sunk or damaged cargo ships can only be successful if containers can withstand water pressure. Next, lifeboats on cargo ships and cruise ships could be transformed into a submarine or research like a vessel. Since many lifeboats sink in the crashing waves of the oceans during the storm, a lifeboat that travels underneath the waves rather than over it makes much more sense. Also, underwater cameras and research vessels could be made from graphene making it lighter and stronger to search for lost historic ships and gold worth billions sunk during World Wars. Not to mention, flatfish could be researched and experimented upon to come up with materials for scuba diving suit and swimwear for extreme underwater pressures. After all, it is one of the very few living things that can exist on the ocean floors of “Mariana’s Trench” under extreme pressures equivalent to “9600 psi”. Moreover, if serpentine rocks or mud volcano is found in abundance in Mariana trench and elsewhere, could it not be used as a lubricant for other subduction zones that actually cause earthquakes? After all, if subduction zones trigger earthquakes and earthquakes trigger volcanoes to erupt both underneath the ocean and on the islands, could the volcanoes not disrupt the magnetic field of the earth which is an assumption to be a result of magnetic rocks on ridges underneath the ocean floor?