Bathymetry in the context of Oceanic plateau

Tides are the rise and fall of sea levels caused by the combined effects of the gravitational forces exerted by the Moon (and to a much lesser extent, the Sun) and are also caused by the Earth and Moon orbiting one another.

Tide tables can be used for any given locale to find the predicted times and amplitude (or "tidal range"). The predictions are influenced by many factors including the alignment of the Sun and Moon, the phase and amplitude of the tide (pattern of tides in the deep ocean), the amphidromic systems of the oceans, and the shape of the coastline and near-shore bathymetry (see Timing). They are however only predictions, and the actual time and height of the tide is affected by wind and atmospheric pressure. Many shorelines experience semi-diurnal tides—two nearly equal high and low tides each day. Other locations have a diurnal tide—one high and low tide each day. A "mixed tide"—two uneven magnitude tides a day—is a third regular category.

The Philippine Sea is a marginal sea of the Western Pacific Ocean east of the Philippine Archipelago and the largest sea in the world, occupying an estimated surface area of 5 million square kilometers (2×10^ sq mi). The Philippine Sea Plate forms the floor of the sea. Its western border is the first island chain to the west, comprising the Ryukyu Islands in the northwest and Taiwan in the west. Its southwestern border comprises the Philippine islands of Luzon, Catanduanes, Samar, Leyte, and Mindanao. Its northern border comprises the Japanese islands of Honshu, Shikoku and Kyūshū. Its eastern border is the second island chain to the east, comprising the Bonin Islands and Iwo Jima in the northeast, the Mariana Islands (including Guam, Saipan, and Tinian) in the due east, and Halmahera, Palau, Yap and Ulithi (of the Caroline Islands) in the southeast. Its southern border is Indonesia's Morotai Island.

The sea has a complex and diverse undersea relief. The floor is formed into a structural basin by a series of geologic faults and fracture zones. Island arcs, which are actually extended ridges protruding above the ocean surface due to plate tectonic activity in the area, enclose the Philippine Sea to the north, east and south. The Philippine archipelago, Ryukyu Islands, and the Marianas are examples. Another prominent feature of the Philippine Sea is the presence of deep sea trenches, among them the Philippine Trench and the Mariana Trench, containing the deepest point on the planet.

Terrain (from Latin terra 'earth'), alternatively relief or topographical relief, is the dimension and shape of a given surface of a land. In physical geography, terrain is the lay of the land. This is usually expressed in terms of the elevation, slope, and orientation of terrain features. Terrain affects surface water flow and distribution. Over a large area, it can affect weather and climate patterns. Bathymetry is the study of underwater relief, while hypsometry studies terrain relative to sea level.

The internal structure of Earth is the layers of the planet Earth, excluding its atmosphere and hydrosphere. The structure consists of an outer silicate solid crust, a highly viscous asthenosphere, and solid mantle, a liquid outer core whose flow generates the Earth's magnetic field, and a solid inner core.

Scientific understanding of the internal structure of Earth is based on observations of topography and bathymetry, observations of rock in outcrop, samples brought to the surface from greater depths by volcanoes or volcanic activity, analysis of the seismic waves that pass through Earth, measurements of the gravitational and magnetic fields of Earth, and experiments with crystalline solids at pressures and temperatures characteristic of Earth's deep interior.

Geomorphology (from Ancient Greek γῆ (gê) 'earth' μορφή (morphḗ) 'form' and λόγος (lógos) 'study') is the scientific study of the origin and evolution of topographic and bathymetric features generated by physical, chemical or biological processes operating at or near Earth's surface. Geomorphologists seek to understand why landscapes look the way they do, to understand landform and terrain history and dynamics and to predict changes through a combination of field observations, physical experiments and numerical modeling. Geomorphologists work within disciplines such as physical geography, geology, geodesy, engineering geology, archaeology, climatology, and geotechnical engineering. This broad base of interests contributes to many research styles and interests within the field.

An altimeter or an altitude meter is an instrument used to measure the altitude of an object above a fixed level. The measurement of altitude is called altimetry, which is related to the term bathymetry, the measurement of depth under water.

Hypsometry (from Ancient Greek ὕψος (húpsos) 'height' and μέτρον (métron) 'measure') is the measurement of the elevation and depth of features of Earth's surface relative to mean sea level.

On Earth, the elevations can take on either positive or negative (below sea level) values. The distribution is theorised to be bimodal due to the difference in density between the lighter continental crust and denser oceanic crust. On other planets within this solar system, elevations are typically unimodal, owing to the lack of plate tectonics on those bodies.

In geodesy, surveying, hydrography and navigation, vertical datum or altimetric datum is a reference coordinate surface used for vertical positions, such as the elevations of Earth-bound features (terrain, bathymetry, water level, and built structures) and altitudes of satellite orbits and in aviation.In planetary science, vertical datums are also known as zero-elevation surface or zero-level reference.

Commonly adopted criteria for a vertical datum include the following approaches:

Physical oceanography is the study of physical conditions and physical processes within the ocean, especially the motions and physical properties of ocean waters.

Physical oceanography is one of several sub-domains into which oceanography is divided. Others include biological, chemical and geological oceanography. Like the study of atmospheric physics, physical oceanography is founded upon principles of thermodynamics and fluid mechanics.

Depth sounding, often simply called sounding, is measuring the depth of a body of water. Data taken from soundings are used in bathymetry to make maps of the floor of a body of water, such as the seabed topography.

Soundings were traditionally shown on nautical charts in fathoms and feet. The National Oceanic and Atmospheric Administration (NOAA), the agency responsible for bathymetric data in the United States, still uses fathoms and feet on nautical charts. In other countries, the International System of Units (metres) has become the standard for measuring depth.

This article lists lakes with a water volume of more than 100 km, ranked by volume. The volume of a lake is a difficult quantity to measure. Generally, the volume must be inferred from bathymetric data by integration. Lake volumes can also change dramatically over time and during the year, especially for salt lakes in arid climates. For these reasons, and because of changing research, information on lake volumes can vary considerably from source to source. The base data for this article are from The Water Encyclopedia (1990). Where volume data from more recent surveys or other authoritative sources have been used, that usage is referenced in the respective entry. The total volume of Earth's lakes is 199,000 km.