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Katla (volcano)
Katla is a large subglacial volcano beneath the Mýrdalsjökull ice cap in southern Iceland, one of the country's most active, with its last confirmed eruption in 1918.
Keeling Curve
The Keeling Curve, begun by Charles David Keeling, is the continuous record of atmospheric carbon dioxide measured at Hawaii's Mauna Loa Observatory since 1958, the longest direct CO2 record.
Keetch–Byram Drought Index
The Keetch–Byram Drought Index (KBDI) is a drought index for forest fire control, developed by John J. Keetch and George M. Byram in 1968, running from 0 to 800.
Kelvin wave
A Kelvin wave is a rotating-fluid wave trapped by the Coriolis effect against a coast or the equator, carrying warm water eastward across the Pacific during El Niño.
Kelvin-Helmholtz cloud
A Kelvin-Helmholtz cloud, or fluctus in the WMO Cloud Atlas, is a short-lived formation of curling, wave-like clouds caused by wind shear, and a source of clear-air turbulence.
Kennecott Utah Copper
Kennecott Utah Copper is a copper mining, smelting, and refining company wholly owned by Rio Tinto, centered on the Bingham Canyon Mine near Salt Lake City, Utah.
Kenorland
Kenorland is a hypothesized Neoarchean supercontinent, proposed in 1991, that joined North American cratons with Baltica and possibly Siberia before breaking up around 2.45 Ga.
Kentucky meat shower
The Kentucky meat shower, also known as Kentucky meat rain, was the fall of raw meat chunks from a clear sky over Bath County, Kentucky, on March 3, 1876.
Kernite
Kernite, formerly rasorite, is a hydrated sodium borate mineral and one of the world's principal ores of boron, discovered in Kern County, California, in 1925.
Kerogen
Kerogen is the insoluble organic matter in sedimentary rocks that generates petroleum and natural gas when buried and heated, and is Earth's most abundant organic matter.
Kettle (landform)
A kettle, also called a kettle hole, is a bowl-shaped depression in glacial deposits formed when a buried ice block melts and overlying sediment collapses.
Keuper
The Keuper is the uppermost of the three lithostratigraphic groups of the Germanic Trias, above the Muschelkalk, consisting mainly of variegated claystones, sandstones, and gypsum deposited in continental, semi-arid conditions.
Keweenaw Peninsula
The Keweenaw Peninsula is the northernmost peninsula of Michigan's Upper Peninsula, projecting northeast into Lake Superior, whose native copper deposits yielded 5 Mt of copper from 1845 to 1968.
Khodutka
Khodutka (Ходутка), also Golygina, is a 2,039 m stratovolcano in southern Kamchatka, Russia. Its VEI 5 Khodutkinsky maar eruption about 2,800 years ago spread tephra across southern Kamchatka; the last summit lava flow dates to about 2,000–2,500 years ago.
Khoemacau
Khoemacau is a copper and silver mine in the Kalahari Copper Belt of northwestern Botswana, owned by MMG Limited and CNIC and producing first concentrate in 2021.
Kidman Resources
Kidman Resources was an Australian mineral exploration company whose work defined the Earl Grey lithium deposit, now the Mount Holland mine; Wesfarmers acquired it in 2019 for about $776 million.
Kigali Amendment
The Kigali Amendment, adopted in Kigali, Rwanda, in 2016, is a binding agreement to phase down HFCs and avoid 0.2 to 0.4 °C of warming by 2100.
Kīlauea
Kīlauea, also known as Kilauea Volcano, is an active shield volcano on the Island of Hawaiʻi and one of the most active on Earth; its 2018 eruption destroyed over 700 structures.
Kimberlite
Kimberlite, also known as blue ground, is an ultramafic volcanic rock occurring in vertical pipes, named after Kimberley, South Africa, and the primary source of diamonds.
Kimmeridge Clay
The Kimmeridge Clay is a gray, organic-rich Jurassic marine mudstone outcropping from Dorset to Yorkshire and is the major oil source rock for the North Sea.
Kincade Fire
The Kincade Fire was a 2019 wildfire near Geyserville in Sonoma County, California, California's largest that year at 77,758 acres, traced to a broken PG&E jumper cable.
Kinematic wave theory
Kinematic wave theory is a simplified description of unsteady shallow water flow in which friction balances the water's weight component, so flow-dependent celerity can steepen waves into shocks.
Kink band
A kink band is a tabular zone, usually mesoscopic, in which a rock's foliation or layering is sharply deflected; kink bands form in strongly layered rocks under compression.
Kinsevere
Kinsevere is an open-pit copper and cobalt mine in Haut-Katanga Province, Democratic Republic of the Congo, owned by MMG Limited and producing LME Grade A copper cathode.
Kittilä mine
Kittilä mine (Kittilän kaivos) is an underground gold mine in Lapland, northern Finland, operated by Agnico Eagle since 2009 and the largest primary gold mine in Europe.
Kiyoo Wadati
Kiyoo Wadati (和達清夫, 1902–1995) was a Japanese seismologist who established that earthquakes occur at depths of several hundred kilometers, and whose name is attached to the Wadati–Benioff zone.
Klerksdorp sphere
Klerksdorp spheres, also called Ottosdal objects, are small pyrite concretions in 3-billion-year-old rock near Ottosdal, South Africa, often promoted as out-of-place artifacts despite geologists classifying them as natural.
Klimaschutzgesetz
The Klimaschutzgesetz, formally the Bundes-Klimaschutzgesetz, is a German federal law enacted in 2019 that sets binding greenhouse gas targets, including 65% below 1990 levels by 2030.
Kohala, Hawaii
Kohala is the oldest, extinct shield volcano of Hawaiʻi Island, forming the island's northwest peninsula and the North and South Kohala districts, with 5,480-ft summit, 0.7 Ma shield age, Pololū landslide, extreme rainfall gradient, Kohala Ditch, and Kamehameha I's birthplace.
Köhler theory
Köhler theory, formulated by Swedish meteorologist Hilding Köhler in 1936, combines the Kelvin and Raoult effects to predict when an aerosol particle activates into a cloud droplet.