December 7, 1941: the Japanese naval fleet attacking Pearl Harbor . Five of the seven American armored are sunk, among them, the USS Arizona , which later became the symbol of the first phase of the battle of the Pacific. A bomb dropped by at 08:06 Hiryu Kate hits the ship on the starboard , resulting in opening a hole in the hull due to the explosion of the ammunition magazine. 
The image below is the only known color camera of the attack on USS Arizona .
The armor is lies on the shallow waters of Pearl Harbor , less than 10 meters deep. After the Japanese attack there were about 2300 victims military almost half of them belonged to the crew of the battleship Arizona.
The part of the story that interests us closer begins when you decide that the wreck is a symbol and for this you need enhance it. Unlike many other famous cases (especially the one Vasa), the choice of the American authorities is to not recovered from the hull bottom . It was decided to erect a platform "Canadian" in the direction perpendicular to the hull (see picture below) is placed on the platform the USS Arizona Memorial , which is visited each year by at least one million people.
The structure of the memorial has an opening on the floor that allows visitors to observe the tank of ship, from which emerge constantly "Tears of the USS Arizona . The hull of the battleship , In fact, fuel lost from the time when it was sunk. For this reason, since 1999 has been developed a multidisciplinary project for and preservation of the hull of ' marine ecosystem on which it stands: the USS Arizona Preservation Project .
The project is a collaboration between the U.S. Geological Survey's Pacific Science Center and the National Park Service. The main issues on which current research focuses are the state of corrosion of the hull and geological structure of the seabed on which the battleship.
How can we imagine the factors that influence the resistance of a metal in the marine environment are numerous, the main parameters that are taken into account are: the pH the concentration of oxygen (oxygen is directly responsible for the corrosion of metal ) and salinity water. In addition to what can be done
campaigns of measures to determine the thickness of the walls the ship's structure. In particular, in a first phase was carried sampling of some sections of the hull (discs with dimensions of 4 inches in diameter), after which it was decided to fall back on a non-invasive technique such as ultrasound probe , considering the importance of the artifact in question.
To assess the rate of corrosion of the hull from the sea water are measurements of corrosion potential (Ecorr). This potential is measured with an electrode Ag / AgCl. By relating the potential with the pH value of water is possible to estimate what the average length of the metal.
The most interesting part of this study is that researchers have developed a system to study the interior of the vessel . In collaboration with a company specializing in underwater filming was made a little-Ray Video ROV (Remotely-Operated Vehicle). This, as well as make video recording transmitted in real time the operator-driver can be equipped with any type of probe in our case, obviously, the researchers decided to equip it with an ultrasound device to assess the thickness of the inner parts of the hull and simultaneously measured the above parameters in areas inaccessible to humans. The picture below shows the ROV used by American researchers.
emerged from the data so far resisted the hull seems to have pretty good marine corrosion.
Another part of monitoring involves the collection (and the subsequent analysis) of concretions found in the outer hull. Particular attention was paid to the ' analysis of colonies of microorganisms present in them in order to understand whether and how microfauna this hull is affecting the corrosion of iron. Preliminary results of this part of the work were published in the new issue of the Journal of Cultural Heritage it is just reading this article I am passionate about the case of the USS Arizona! Through
probes GPS, position in strategic areas of the ship, the position of the hull is kept under constant control ; areas around the hole were placed motion detectors, as is done with a masonry structural cracks.
Finally, as mentioned earlier, all combined ' analysis of the movements of the hull and a detailed geological study of the sediments Bay's Pearl Harbor which lies on the battleship, will enable scientists to ensure that this symbol of the history American and submerged a peaceful rest for at least another hundred years!
The image below is the only known color camera of the attack on USS Arizona . 
The armor is lies on the shallow waters of Pearl Harbor , less than 10 meters deep. After the Japanese attack there were about 2300 victims military almost half of them belonged to the crew of the battleship Arizona.
The part of the story that interests us closer begins when you decide that the wreck is a symbol and for this you need enhance it. Unlike many other famous cases (especially the one Vasa), the choice of the American authorities is to not recovered from the hull bottom . It was decided to erect a platform "Canadian" in the direction perpendicular to the hull (see picture below) is placed on the platform the USS Arizona Memorial , which is visited each year by at least one million people.
The structure of the memorial has an opening on the floor that allows visitors to observe the tank of ship, from which emerge constantly "Tears of the USS Arizona . The hull of the battleship , In fact, fuel lost from the time when it was sunk. For this reason, since 1999 has been developed a multidisciplinary project for and preservation of the hull of ' marine ecosystem on which it stands: the USS Arizona Preservation Project .
The project is a collaboration between the U.S. Geological Survey's Pacific Science Center and the National Park Service. The main issues on which current research focuses are the state of corrosion of the hull and geological structure of the seabed on which the battleship.
How can we imagine the factors that influence the resistance of a metal in the marine environment are numerous, the main parameters that are taken into account are: the pH the concentration of oxygen (oxygen is directly responsible for the corrosion of metal ) and salinity water. In addition to what can be done
campaigns of measures to determine the thickness of the walls the ship's structure. In particular, in a first phase was carried sampling of some sections of the hull (discs with dimensions of 4 inches in diameter), after which it was decided to fall back on a non-invasive technique such as ultrasound probe , considering the importance of the artifact in question.
To assess the rate of corrosion of the hull from the sea water are measurements of corrosion potential (Ecorr). This potential is measured with an electrode Ag / AgCl. By relating the potential with the pH value of water is possible to estimate what the average length of the metal.
The most interesting part of this study is that researchers have developed a system to study the interior of the vessel . In collaboration with a company specializing in underwater filming was made a little-Ray Video ROV (Remotely-Operated Vehicle). This, as well as make video recording transmitted in real time the operator-driver can be equipped with any type of probe in our case, obviously, the researchers decided to equip it with an ultrasound device to assess the thickness of the inner parts of the hull and simultaneously measured the above parameters in areas inaccessible to humans. The picture below shows the ROV used by American researchers.
emerged from the data so far resisted the hull seems to have pretty good marine corrosion. Another part of monitoring involves the collection (and the subsequent analysis) of concretions found in the outer hull. Particular attention was paid to the ' analysis of colonies of microorganisms present in them in order to understand whether and how microfauna this hull is affecting the corrosion of iron. Preliminary results of this part of the work were published in the new issue of the Journal of Cultural Heritage it is just reading this article I am passionate about the case of the USS Arizona! Through
probes GPS, position in strategic areas of the ship, the position of the hull is kept under constant control ; areas around the hole were placed motion detectors, as is done with a masonry structural cracks.
Finally, as mentioned earlier, all combined ' analysis of the movements of the hull and a detailed geological study of the sediments Bay's Pearl Harbor which lies on the battleship, will enable scientists to ensure that this symbol of the history American and submerged a peaceful rest for at least another hundred years!
