2024年6月16日 · The Great Loop is a continuous waterway that recreational mariners can travel that includes part of the Atlantic, Gulf Intracoastal Waterways, the Great Lakes, Canadian Heritage Canals, and the inland rivers of America's heartland.

The simplest model of the Earth is a sphere. A much more complex model of the Earth is the geoid, used to approximate mean sea level. Even the geoid is a simplified model, however, when compared to actual topographic relief, as shown in this …

2024年6月16日 · Natural disasters such as hurricanes, tropical storms, tsunamis, and landslides have the potential to be the source of a tremendous amount of marine debris. High winds, heavy rain, storm surge, and flooding associated with these disasters can pull large structures, household products, and outdoor items into surrounding waters.

2024年6月16日 · At the height of World War II, scientists tested a theory that low-frequency sound could travel long distances in the deep ocean. They deployed a hydrophone from their research vessel, which was anchored off of Woods Hole, Massachusetts. Some 900 miles away, another ship lowered a four-pound explosive to a specific depth below the ocean surface.

The Charles W. Morgan is the last of an American whaling fleet that once numbered more than 2,700 vessels. Ships like the Morgan often used routes defined by the trade winds to navigate the ocean.. Known to sailors around the world, the trade winds and associated ocean currents helped early sailing ships from European and African ports make their journeys to the Americas.

In the U.S., where over half of us live along the coast and more than 78 percent of our overseas trade by volume comes and goes along our marine highways, the health of our coasts is intricately connected to the health of our nation's economy. The National Ocean Service (NOS) translates science, tools, and services into action, to address threats to coastal areas such as climate …

Each year, millions of tons of trash and other debris enters our ocean, and thousands of oil spills occur in U.S. waters. And pollution from other sources, like fertilizer from our yards, builds up in waterways and causes explosions of algae growth, which can be harmful to the environment and even toxic to humans.

Waterspouts fall into two categories: fair weather waterspouts and tornadic waterspouts. Tornadic waterspouts are tornadoes that form over water, or move from land to water. They have the same characteristics as a land tornado. They are associated with severe thunderstorms, and are often accompanied by high winds and seas, large hail, and frequent dangerous lightning.

Coral reefs are some of the most diverse ecosystems in the world. Thousands of species rely on reefs for survival. Millions of people all over the world also depend on coral reefs for food, protection and jobs. This tutorial is an overview of the biology of and threats to coral reefs, as well as efforts being made to conserve and protect them. It includes images, animations, and videos.

Gravity is one major force that creates tides. In 1687, Sir Isaac Newton explained that ocean tides result from the gravitational attraction of the sun and moon on the oceans of the earth (Sumich, J.L., 1996).