The ocean known for its deep underwater trenches is the Pacific Ocean. It contains the world's deepest points, including the Mariana Trench. This ocean is vast and influential, encompassing more than 63 million square miles and playing a crucial role in global climate and weather patterns. The formation of its trenches is a result of tectonic activity, where oceanic plates subduct beneath continental or other oceanic plates. These trenches, including the Japan Trench and Tonga Trench, are significant areas for scientific research due to their unique ecosystems and geological features, which present opportunities for studying the Earth's history.