Earth sciences

Santorini caldera

The Santorini caldera is a large, largely submerged volcanic caldera in the Aegean Sea, flooded as a bay ringed by the cliffs of Thera and Therasia.

Santos Basin

The Santos Basin is an offshore sedimentary basin along Brazil's southeastern coast; the 2006 Lula (Tupi) discovery made it Brazil's leading oil-producing province, led by the pre-salt fields.

Sapphire

Sapphire is the gem variety of the mineral corundum, blue by convention but covering every color except red, which is ruby; Kashmir stones command the highest prices.

SAR tomography

SAR tomography (TomoSAR) is a radar technique that reconstructs 3D images of scenes from multiple radar passes, first demonstrated in 2000 and used for forests, cities, and ice.

The Saraswati River (Sanskrit: Sarasvati) is a lost river of northwest India praised in the Rigveda and identified with the Ghaggar-Hakra system, whose dry bed runs through Punjab, Haryana, and Rajasthan.

Satellite altimetry

Satellite altimetry is a remote-sensing technique that measures sea surface height, ice, and inland waters by timing radar or laser pulses, supporting sea level monitoring since 1973.

Satellite clock estimation

Satellite clock estimation determines GNSS satellite clock offsets and drifts from code and carrier-phase observations at ground stations, underpinning precise point positioning and real-time navigation.

Satellite laser ranging

Satellite laser ranging (SLR) is a geodetic technique that measures round-trip laser pulse times to satellites carrying retroreflectors, deriving orbits, station positions, and Earth's gravity field.

Satellite remote sensing of the ocean

Satellite remote sensing of the ocean is the measurement of sea surface properties from orbit using electromagnetic sensors instead of ships and buoys, observing sea level, winds, temperature, ice, and color.

Satellite-derived bathymetry

Satellite-derived bathymetry (SDB) is the calculation of shallow water depth from satellite sensors, a low-cost remote alternative to surveys in inaccessible areas, formally guided by the IHO since 2024.

Saturation vapor pressure

Saturation vapor pressure is the pressure of a vapor in equilibrium with its liquid or solid at a given temperature, rising rapidly as temperature increases.

Scale height

Scale height is the vertical distance over which atmospheric pressure or density falls by a factor of e, about 8.4 km on Earth and 5 to 20 km on most planets.

Scandinavia pattern

The Scandinavia pattern (SCAND), originally called the Eurasia-1 pattern, is a Northern Hemisphere teleconnection pattern whose main pressure center sits over Scandinavia, linked to Scandinavian blocking and European weather impacts.

Scatterometer

A scatterometer is a radar instrument that measures ocean surface wind speed and direction from the backscatter of microwave pulses, first demonstrated on Skylab in 1973.

Scheelite

Scheelite is a calcium tungstate mineral, CaWO4, one of the two principal ores of tungsten, found mainly in skarn and prized for its bluish-white fluorescence under ultraviolet light.

Schist

Schist is a medium-grade foliated metamorphic rock whose aligned platy minerals, especially mica, give it a layered texture and let it split readily into thin flakes or slabs.

Schlumberger array

The Schlumberger array is a four-electrode configuration for measuring the electrical resistivity of the ground, with closely spaced potential electrodes, and the most common configuration for vertical electrical sounding.

Schorl

Schorl is the sodium-iron, always-black member of the tourmaline mineral group, making up roughly 95 percent of all tourmaline in nature and first described in 1505.

Schreibersite

Schreibersite is an iron–nickel phosphide mineral, (Fe,Ni)₃P, that occurs in nearly all iron meteorites and is a leading candidate for the reactive phosphorus prebiotic chemistry needed on the early Earth.

Schumann resonances

Schumann resonances, also called Earth-ionosphere cavity resonances, are electromagnetic oscillations near 8, 14, 20, 27, and 34 Hz excited by global lightning, predicted in 1952.

Schwertmannite

Schwertmannite is a poorly crystalline iron(III) oxyhydroxy-sulfate mineral with formula Fe₈O₈(OH)₈₋₂ₓ(SO₄)ₓ·nH₂O, recognized in 1992 and named for soil scientist Udo Schwertmann, forming yellowish-brown ochre precipitates in acidic mine drainage.

Science Based Targets initiative

The Science Based Targets initiative (SBTi) is a charity that validates corporate emissions reduction targets against climate science, founded by CDP, the UN Global Compact, and WWF.

Scientific Committee on Oceanic Research

The Scientific Committee on Oceanic Research (SCOR) is an international non-governmental organization founded in 1957 by the International Council of Scientific Unions to promote and coordinate international ocean science.

Scientific consensus on climate change

The scientific consensus on climate change, also known as scientific opinion on global warming, is the agreement that human activities have unequivocally caused about 1.1 °C of warming, endorsed by over 99% of climate scientists.

Scientific drilling

Scientific drilling is a research method that recovers samples from beneath the seafloor and continental crust, verifying geophysical models and extending the marine record back 200 million years.

Scientific outfitting of research vessels

Scientific outfitting of research vessels is the design of a ship's winches, cranes, deck machinery, laboratories, and hull-mounted acoustic sensors as one integrated system for deploying scientific instruments.

Scope 1, 2, and 3 emissions

Scope 1, 2, and 3 emissions are the three categories into which the Greenhouse Gas Protocol divides a company's emissions, covering direct operations, purchased energy, and the value chain.

Scoria

Scoria is a dark-colored, highly vesicular volcanic rock formed when gas bubbles are trapped in solidifying magma; it builds cinder cones, sinks in water unlike pumice, and is crushed for lightweight concrete.

Scree

Scree, also known as talus, is a deposit of loose, angular rock fragments at the base of a cliff or steep slope, formed by rockfall.