Ocean drilling is the process by which scientists drill into the Earth's ocean crust to collect sample cores of rock. This has allowed scientists to obtain samples of fluids, and microbes contained in the core samples. Scientific drilling is carried out in the ocean by the Integrated Ocean Drilling Program (IODP). For more than forty years, ocean drilling has contributed to expand the knowledge in a wide range of earth science disciplines, including biology, chemistry and geology of the Earth. This has allowed scientist to understand global climate change over the last 65 million years, plate tectonics and the microbial and fluid composition of the ocean floor.
Sediment deposits in the ocean floor
The sediment deposits in the ocean floor contain records of chemical, biological, and the geological processes that the Earth has gone through for the past millions of years. Over the past decades, scientists have explored this information through ocean drilling. In order to obtain this broad of information, scientists extract cores of sediment from the ocean floor and bring them to the surface for study. After the cores have been drilled, scientists install sensors in the holes left in order to learn about the biological, chemical and geological processes that affect the Earth.
Ocean drilling has improved the understanding of the chemistry, biology and physical properties within the ocean's crust. It has expanded the knowledge about the Earth's climate history, and the Earth's origin and evolution. Research done over the last four decades has broaden the scientist's understanding of plate tectonics, variations in the Earth's magnetic field, the structure of the ocean crust and upper mantle and the processes by which earthquakes and tsunamis occur. Ocean drilling has also stimulated the improvement of technologies for the further advancement of ocean drilling research.
Life in the ocean floor
Drilling into the sea floor has contributed to a more ample understanding of the hydrogeological processes occurring there. This has led to a better understanding of hydrothermal vents and the way in which rocks and fluids interact . Ocean drilling has increased the knowledge of the interaction between fluids and rocks to form massive sulfide deposits in the ocean's hydrothermal vents. It has also allowed to study microbes below the ocean floor, increasing the understanding of microbial communities thriving in the deep ocean.
Ocean drilling has provided an increased understanding of the Earth's climate history over the past 65 million years. The long sediment cores that have been extracted through ocean drilling have revealed a record of the way in which the Earth's climate has changed throughout its history. The ocean sediment cores also provide information about carbon dioxide (CO2) levels in the past, This may allow scientists to understand the way in which the planet will respond to changing levels of CO2 in the future.
The Integrated Ocean Drilling Program (IODP) is an international research endeavor that explores the structure of the Earth and its history. The IODP covers a number of research objectives, among which include three main themes intended to understand the deep biosphere: the way in which the sub-ocean floor is composed; understand the change in the environment of the sea floor and the processes that affect it; understand the cycles and geodynamics of the earth. The IOPD may help to make significant advances in new areas of research.
Although the initial objective of drilling in the ocean was to test the theory of plate tectonics, the discoveries made in the fields of biology, chemistry and geology, among others, provided the basis for further advancement into ocean drilling. According to divediscover.whoi.edu, the cores extracted did not only confirmed seafloor spreading and plate tectonics, but they also uncovered much more information than that, as the accumulated layers in the cores contained the recorded Earth's climate history, as well as its structure and evolution.