Planet Field Guide

A numerical estimate of earthquake size at its source.

The strength of earthquake shaking at a particular place.

The surface position directly above the underground starting point of an earthquake.

The point inside Earth where earthquake rupture begins.

The reported vertical distance below the surface to an earthquake's origin.

A seismic event with depth under approximately 70 kilometers.

An earthquake originating about 70–300 kilometers below the surface.

An event originating more than roughly 300 kilometers underground.

An instrument that records seismic ground motion.

The selected public feed contains reported events meeting its magnitude and time rules.

Molten or partially molten rock below Earth's surface.

Molten rock that has reached Earth's surface.

Fine fragments of volcanic rock, minerals and glass released in an eruption.

A large volcanic depression that can form when underlying support collapses.

A volcano built by repeated layers of lava and fragmented erupted material.

A broad, gently sloping volcano often built from fluid basaltic lava.

A hot, fast-moving mixture of gas, ash and rock fragments from volcanic activity.

A flow of water mixed with volcanic debris and sediment.

A curated catalog of natural events with published categories and geometries.

A spatial outline or other geometry representing the area associated with an event.

The periodic rise and fall of sea level driven primarily by lunar and solar gravity.

Movement of ocean water driven by winds, tides and density differences.

A measure of dissolved salts in water.

A measure or estimate of the temperature near the top of the ocean.

Ocean circulation associated with temperature and salinity differences that affect density.

Water moves among evaporation, condensation, precipitation, runoff and storage.

A sediment accumulation area associated with a river outlet or basin.

A biologically rich habitat built in part by reef-forming corals.

Sea ice freezes from seawater; an iceberg breaks from glacial ice.

Weather describes shorter-term conditions; climate describes longer-term patterns.

A planetary-scale index of geomagnetic disturbance reported in three-hour intervals.

Geomagnetic Kp values range from 0 through 9.

The NOAA G1 minor geomagnetic-storm classification begins at Kp 5.

Kp represents a three-hour measurement interval.

Charged particles streaming outward from the Sun.

A region surrounding Earth strongly controlled by its magnetic field.

Light emitted when energetic particles interact with upper-atmosphere gases.

Coordinated Universal Time aligns magnetic measurements worldwide.

The approximate division between sunlit and dark hemispheres of Earth.

An explicitly illustrative marker used for interaction demonstrations.

An angular position north or south of the Equator, from minus to plus 90 degrees.

An angular position east or west of the prime meridian.

The shortest surface distance on an ideal sphere between two coordinates.

A date and time expressed in Coordinated Universal Time.

An image representation using colors similar to human vision.

Collecting data from a distance with sensors, commonly on aircraft or satellites.

Measurements describe observed signals; models compute estimates using inputs and assumptions.

The age of a provider's observation or downloaded data.

An unknown measurement means there is no usable value; zero is a numerical value.

A dataset includes only records inside its selected thresholds, time span and geography.