Timeline of United States discoveries four days into the ship's maiden voyage, "Titanic" struck an iceberg and sank two hours and forty minutes later, early on April 15, 1912. The sinking resulted in the deaths of 1,517 of the 2,223 people on board, making it one of the deadliest peacetime maritime disasters in history. After nearly 74 years of being lost at sea on the bottom of the ocean floor, a joint Franco-American expedition led by American oceanographer Dr. Robert D. Ballard, discovered the wreckage of the RMS "Titanic" two miles (3 km) beneath the waves of the North Atlantic on September 1, 1985. Ballard
Geology of the Pacific Ocean . The Pacific Ocean developed from the Panthalassa, a vast global ocean, following the breakup of the supercontinent Pangaea in the Mesozoic Era, gradually forming Gondwana and Laurasia, which in turn divided. There is no firm date for when the changeover occurred, as the replacement of the sea bed is a continuous process, though reconstruction maps often change the name from Panthalassic to Pacific around the time the Atlantic Ocean began to open. The Panthalassic Ocean first opened around 750 million years ago at the breakup of Rodinia, but the oldest Pacific Ocean floor is only around 180 Ma old.