Exploration at sea
Once at sea the science work can begin. Different scientists will be interested in different areas of the sea; geoscientists are generally interested in the ocean floor, bio-geochemists may investigate the water column and the ecosystems that support marine life, while physicists and climate modellers tend to focus on the surface and above. No matter the area of study a scientist requires the correct equipment to perform an investigation.
The bottom of a body of water is known as the benthic zone, regardless of how deep it occurs. In coastal waters the sea floor sits upon the continental shelf and is generally less than 200m deep. The majority of the ocean floor lies upon the ocean crust and is between 4000m to 6000m deep. Working at such depths requires specialist tools and skills to obtain the data needed.
The water column extends from the top of the surface to the bottom of the floor. When studying the ocean, the depth of the water column can be a great as 11km! That is even taller than Mount Everest - the highest point on Earth. Scientists describe the water column by dividing it into layers that have certain features.
The oceans contain an amazing variety of life, from the tiniest - Femtoplankton, to the largest - Blue Whale. Marine life can be found in some extreme environments; in water temperatures higher than a 100ºC and lower than 0ºC. In the deepest parts life still exists; living under pressure that is as great as 1.1 tonnes per square centimetre (8 tons per square inch or 1079 bar), that’s over thousand times greater than it is at the surface.
The surface of the sea can be considered anything from the first millimetre to tens of meters deep depending on what is being looked at. Scientists who want to know about the surface of the ocean might be interested in what it can tell us about weather and climate processes, or how the air and sea affect each other. Environmental conditions also affect ecosystems, coastal erosion and other areas, so are important to many scientists.