Thermokarst
Thermokarst is the process and landscape pattern that develops when ice-rich permafrost thaws, causing the ground to collapse, slump, pond, or form irregular terrain.
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Earth Science Topics
Browse Qlopedia topics grouped under Earth Science.
121 topics, showing 1-24 on page 1 of 6.
Topics
Cryosphere
The cryosphere is the frozen part of Earth: snow, sea ice, glaciers, ice sheets, ice shelves, frozen lakes and rivers, permafrost, and seasonally frozen ground. It stores freshwater, reflects sunlight, shapes ecosystems, influences sea level, and responds quickly to climate change.
Prescribed Fire
Prescribed fire is the planned use of fire under specific weather, fuel, staffing, and safety conditions. It can reduce hazardous fuels, restore fire-adapted ecosystems, support cultural land stewardship, and lower some wildfire risks, but it also requires careful planning because smoke, escapes, and public safety remain real concerns.
Microclimates
Microclimates are local climate conditions that differ from the surrounding area. A shaded courtyard, sunny slope, frost hollow, forest edge, beach, rooftop, or street canyon can have its own pattern of temperature, humidity, wind, sunlight, and moisture, even when it shares the same regional weather forecast.
Biogeochemical cycle
A biogeochemical cycle is the movement and transformation of elements or compounds through living organisms, rocks, water, air, and chemical reactions.
The sulfur cycle
The sulfur cycle is the movement of sulfur among rocks, soils, water, organisms, the atmosphere, and sediments through chemical and microbial transformations.
Hydrothermal vent
A hydrothermal vent is a seafloor opening where seawater heated by hot rock returns to the ocean carrying dissolved minerals and chemical energy.
Silica sinter
Silica sinter is a hard mineral deposit that forms when silica-rich hot spring or geyser water cools and leaves opaline silica behind.
Travertine terrace
A travertine terrace forms where mineral-rich hot spring water loses carbon dioxide and deposits calcium carbonate in stepped, flowing layers.
Mudpot
A mudpot is an acidic hydrothermal feature where steam, gases, water, and altered rock mix into bubbling clay-rich mud.
Hot spring
A hot spring forms where groundwater heated underground reaches the surface, often carrying dissolved minerals and heat from volcanic or deep geologic systems.
Geyser
A geyser is a hot spring with plumbing tight enough to let heat, water, and pressure build until water and steam burst upward.
Fumarole
A fumarole is a vent or crack where steam and volcanic gases escape from hot rock, magma-heated groundwater, or a hydrothermal system. Fumaroles can reveal volcanic heat, gas chemistry, sulfur deposition, hydrothermal alteration, unrest, and hazards even when no lava is erupting.
Caldera
A caldera is a large volcanic depression, usually formed when the ground above a magma reservoir collapses after magma is withdrawn during an eruption or intrusion. Calderas can host lakes, lava domes, resurgent uplifts, hydrothermal systems, renewed eruptions, and long-lived volcanic hazards.
Lahar
A lahar is a fast-moving volcanic mudflow or debris flow made of water, ash, rock fragments, sediment, and volcanic debris. Lahars can rush down river valleys during or after eruptions, travel far from a volcano, bury channels and floodplains, and threaten communities long after explosive activity has stopped.
Tephra
Tephra is volcanic material blasted into the air during an eruption and deposited from the atmosphere. It includes ash, lapilli, blocks, bombs, pumice, glass shards, crystals, and older rock fragments, and it can record eruption style, wind direction, hazards, and geologic time markers.
Pyroclastic flow
A pyroclastic flow is a fast-moving, ground-hugging mixture of hot volcanic gas, ash, pumice, and rock fragments. It is one of the most dangerous volcanic hazards because it can move rapidly down slopes and valleys, remain extremely hot, and destroy or bury almost everything in its path.
Lava
Lava is molten or partly molten rock that has erupted onto a planetary surface. On Earth, lava flows, fountains, domes, tubes, and volcanic fragments reveal magma composition, eruption style, cooling rate, gas release, terrain, and volcanic hazards.
Magma
Magma is molten or partly molten rock beneath Earth surface. It can contain liquid melt, crystals, dissolved gases, and bubbles, and it is the source material for igneous rocks, volcanic eruptions, lava flows, intrusions, and many mineral deposits.
Sedimentary rock
Sedimentary rock forms from particles, minerals, organic material, or chemical precipitates deposited at or near Earth surface. It often preserves layers, fossils, sedimentary structures, and environmental clues that help geologists reconstruct rivers, deserts, lakes, coastlines, oceans, and ancient climates.
Igneous rock
Igneous rock forms when molten rock cools and solidifies. It includes intrusive rocks that crystallize below the surface, extrusive volcanic rocks that cool at or near the surface, and many textures that record cooling rate, gas content, mineral composition, and eruption or intrusion history.
Rock cycle
The rock cycle describes how rocks form, break down, transform, melt, and reform through geologic time. It connects igneous, sedimentary, and metamorphic rocks through processes such as cooling, weathering, erosion, burial, lithification, metamorphism, uplift, and melting.
Metamorphism
Metamorphism is the solid-state transformation of existing rock as temperature, pressure, stress, and chemically active fluids change. It creates metamorphic minerals, textures, and rock types that record burial, mountain building, subduction, intrusion, and deformation.
Orogeny
Orogeny is the long geologic process of mountain building. It usually happens where tectonic plates converge, compressing, folding, faulting, thickening, heating, uplifting, and eroding crust into mountain belts over millions of years.