Not too long ago, scientists studying the ocean made a fascinating discovery that has helped us better understand our planet Earth. Down in the deep and dark waters, they found hot springs on the ocean floor releasing warm and mineral-rich fluids - these are called hydrothermal vents. Hydrothermal vents are often associated with undersea volcanoes. This is because the vents are created and sustained by the heat of volcanic activity at tectonic plate boundaries, found throughout the globe. At these locations, seawater seeps through cracks in the seafloor and is heated by molten rock. This causes chemical reactions between the two, and the altered seawater becomes hydrothermal fluid. This hot fluid then jets back into the ocean, forming a hydrothermal vent. Despite the seemingly harsh volcanic environment, these vents are actually home to a variety of life. Microbes, such as bacteria and archaea, live here - harvesting chemical energy from the hydrothermal fluid. These microbes form the base of a unique food chain that includes tubeworms, shrimp, and even crabs that live in communities around the vents. It's hard to find vents and active volcanoes in the deep ocean. To do so, scientists can use a CTD instrument package that measures the conductivity, temperature, and depth in the ocean. Changes in temperature and the cloudiness of the water may be a sign of a hot spring site or erupting underwater volcano. The discovery of these vents and volcanoes has revealed new ecosystems we didn't know existed, and has taught us new things about how the Earth works. Scientists are sure to learn a lot more from the eruption of information that these deep ocean spectacles provide.