Portal:Earth sciences

The retreat of glaciers since 1850 is a well-documented effect of climate change. The retreat of mountain glaciers provides evidence for the rise in global temperatures since the late 19th century. Examples include mountain glaciers in western North America, Asia, the Alps in central Europe, and tropical and subtropical regions of South America and Africa. Since glacial mass is affected by long-term climatic changes, e.g. precipitation, mean temperature, and cloud cover, glacial mass changes are one of the most sensitive indicators of climate change. The retreat of glaciers is also a major reason for sea level rise. Excluding peripheral glaciers of ice sheets, the total cumulated global glacial losses over the 26 years from 1993 to 2018 were likely 5500 gigatons, or 210 gigatons per year.

On Earth, 99% of glacial ice is contained within vast ice sheets (also known as "continental glaciers") in the polar regions. Glaciers also exist in mountain ranges on every continent other than the Australian mainland, including Oceania's high-latitude oceanic island countries such as New Zealand. Glacial bodies larger than 50,000 km² (19,000 sq mi) are called ice sheets. They are several kilometers deep and obscure the underlying topography. (Full article...)

Hurricane Isabel was a Category 5 Atlantic hurricane that struck the east coast of the United States in September 2003. The ninth named storm, fifth hurricane, and second major hurricane of the season, Isabel formed in the eastern Atlantic Ocean on September 6 from a tropical wave. It moved northwestward through an area with light wind shear and warm waters, resulting in strengthening. Isabel reached peak winds of 165 mph (266 km/h) on September 11. After fluctuating in intensity for four days, Isabel gradually weakened and made landfall on the Outer Banks of North Carolina, with winds of 105 mph (169 km/h) on September 18, or a Category 2 on the Saffir-Simpson scale. Isabel quickly weakened over land and became extratropical over western Pennsylvania on the next day. On September 20, the extratropical remnants of Isabel were absorbed into another system over Eastern Canada.

In North Carolina, the storm surge from Isabel washed out a portion of Hatteras Island to form what was unofficially known as Isabel Inlet. Damage was greatest along the Outer Banks, where thousands of homes were damaged or even destroyed. The worst of the effects of Isabel occurred in Virginia, especially in the Hampton Roads area and along the shores of rivers as far west and north as Richmond and Baltimore. Virginia reported the most deaths and damage from the hurricane. About 64% of the damage and 69% of the deaths occurred in North Carolina and Virginia. Electric service was disrupted in areas of Virginia for several days, some more rural areas were without electricity for weeks, and local flooding caused thousands of dollars in damage. (Full article...)

Present-day climate change includes both global warming—the ongoing increase in global average temperature—and its wider effects on Earth's climate system. Climate change in a broader sense also includes previous long-term changes to Earth's climate. The current rise in global temperatures is driven by human activities, especially fossil fuel burning since the Industrial Revolution. Fossil fuel use, deforestation, and some agricultural and industrial practices release greenhouse gases. These gases absorb some of the heat that the Earth radiates after it warms from sunlight, warming the lower atmosphere. Carbon dioxide, the primary gas driving global warming, has increased in concentration by about 50% since the pre-industrial era to levels not seen for millions of years.

Climate change has an increasingly large impact on the environment. Deserts are expanding, while heat waves and wildfires are becoming more common. Amplified warming in the Arctic has contributed to thawing permafrost, retreat of glaciers and sea ice decline. Higher temperatures are also causing more intense storms, droughts, and other weather extremes. Rapid environmental change in mountains, coral reefs, and the Arctic is forcing many species to relocate or become extinct. Even if efforts to minimize future warming are successful, some effects will continue for centuries. These include ocean heating, ocean acidification and sea level rise. (Full article...)

Yellowstone National Park is a national park of the United States located in the northwest corner of Wyoming, with small portions extending into Montana and Idaho. It was established by the 42nd U.S. Congress through the Yellowstone National Park Protection Act and signed into law by President Ulysses S. Grant on March 1, 1872. Yellowstone was the first national park in the US, and is also widely understood to be the first national park in the world. The park is known for its wildlife and its many geothermal features, especially the Old Faithful geyser, one of its most popular. While it represents many types of biomes, the subalpine forest is the most abundant. It is part of the South Central Rockies forests ecoregion.

While Native Americans have lived in the Yellowstone region for at least 11,000 years, aside from visits by mountain men during the early-to-mid-19th century, organized exploration did not begin until the late 1860s. Management and control of the park originally fell under the jurisdiction of the U.S. Department of the Interior, the first secretary of the interior to supervise the park being Columbus Delano. However, the U.S. Army was eventually commissioned to oversee the management of Yellowstone for 30 years between 1886 and 1916. In 1917, the administration of the park was transferred to the National Park Service, which had been created the previous year. Hundreds of structures have been built and are protected for their architectural and historical significance, and researchers have examined more than one thousand indigenous archaeological sites. (Full article...)

A geyser (/ˈɡaɪzər/, UK: /ˈɡiːzər/) is a spring with an intermittent water discharge ejected turbulently and accompanied by steam. The formation of geysers is fairly rare and is caused by particular hydrogeological conditions that exist only in a few places on Earth.

Generally, geyser field sites are located near active volcanic areas, and the geyser effect is due to the proximity of magma. Surface water works its way down to an average depth of around 2,000 metres (6,600 ft) where it contacts hot rocks. The pressurized water boils, and this causes the geyser effect of hot water and steam spraying out of the geyser's surface vent. (Full article...)

In 1257, a catastrophic eruption occurred at Samalas, a volcano on the Indonesian island of Lombok. The event had a probable Volcanic Explosivity Index of 7, making it one of the largest volcanic eruptions during the Holocene epoch. It left behind a large caldera that contains Lake Segara Anak. Later volcanic activity created more volcanic centres in the caldera, including the Barujari cone, which remains active.

The event created eruption columns reaching tens of kilometres into the atmosphere and pyroclastic flows that buried much of Lombok and crossed the sea to reach the neighbouring island of Sumbawa. The flows destroyed human habitations, including the city of Pamatan, which was the capital of a kingdom on Lombok. Ash from the eruption fell as far as 340 kilometres (210 mi) away in Java; the volcano deposited more than 10 cubic kilometres (2.4 cu mi) of rocks and ash. (Full article...)

Turquoise is an opaque, blue-to-green mineral that is a hydrous phosphate of copper and aluminium, with the chemical formula CuAl₆(PO₄)₄(OH)₈·4H₂O. It is rare and valuable in finer grades and has been prized as a gemstone for millennia due to its hue.

The robin egg blue or sky blue color of the Persian turquoise mined near the modern city of Nishapur, Iran, has been used as a guiding reference for evaluating turquoise quality. (Full article...)

Archaeopteryx (/ˌɑːrkiːˈɒptərɪks/ ^ⓘ; lit. 'ancient wing'), sometimes referred to by its German name, "Urvogel" (lit. Primeval Bird) is a genus of bird-like dinosaurs. The name derives from the ancient Greek ἀρχαῖος (archaîos), meaning "ancient", and πτέρυξ (ptéryx), meaning "feather" or "wing". Between the late 19th century and the early 21st century, Archaeopteryx was generally accepted by palaeontologists and popular reference books as the oldest known bird (member of the group Avialae). Older potential avialans have since been identified, including Anchiornis, Xiaotingia, Aurornis, and Baminornis.

Archaeopteryx lived in the Late Jurassic around 150 million years ago, in what is now southern Germany, during a time when Europe was an archipelago of islands in a shallow warm tropical sea, much closer to the equator than it is now. Similar in size to a Eurasian magpie, with the largest individuals possibly attaining the size of a raven, the largest species of Archaeopteryx could grow to about 0.5 m (1 ft 8 in) in length. Despite their small size, broad wings, and inferred ability to fly or glide, Archaeopteryx had more in common with other small Mesozoic dinosaurs than with modern birds. In particular, they shared the following features with the dromaeosaurids and troodontids: jaws with sharp teeth, three fingers with claws, a long bony tail, hyperextensible second toes ("killing claw"), feathers (which also suggest warm-bloodedness), and various features of the skeleton. (Full article...)

Mary Anning (21 May 1799 – 9 March 1847) was an English fossil collector, dealer, and palaeontologist. She became known internationally for her discoveries in Jurassic marine fossil beds in the cliffs along the English Channel at Lyme Regis in the county of Dorset, Southwest England. Anning's findings contributed to changes in scientific thinking about prehistoric life and the history of the Earth.

Anning searched for fossils in the area's Blue Lias and Charmouth Mudstone cliffs, particularly during the winter months when landslides exposed new fossils that had to be collected quickly before they were lost to the sea. Her discoveries included the first correctly identified ichthyosaur skeleton when she was twelve years old; the first two nearly complete plesiosaur skeletons; the first pterosaur skeleton located outside Germany; and fish fossils. Her observations played a key role in the discovery that coprolites, known as bezoar stones at the time, were fossilised faeces, and she also discovered that belemnite fossils contained fossilised ink sacs like those of modern cephalopods. (Full article...)

The 1867 Manhattan earthquake struck Riley County, Kansas, in the United States on April 24, 1867, at 20:22 UTC, or about 14:30 local time. The strongest earthquake to originate in the state, it measured 5.1 on a seismic scale that is based on an isoseismal map or the event's felt area. The earthquake's epicenter was near the town of Manhattan.

The earthquake had a maximum perceived intensity of VII (Very strong) on the Mercalli intensity scale. It caused minor damage, reports of which were confined to Kansas, Iowa, and Missouri, according to the United States Geological Survey. Felt over an area of 200,000 square miles (520,000 km²), the earthquake reached the states of Indiana, Illinois, and possibly Ohio, though the latter reports have been questioned. (Full article...)

Hurricane Gloria was a powerful tropical cyclone that caused significant damage along the East Coast of the United States and in Atlantic Canada during the 1985 Atlantic hurricane season. It was the first significant tropical cyclone to strike the northeastern United States since Hurricane Agnes in 1972 and the first major storm to affect New York City and Long Island directly since Hurricane Donna in 1960. Gloria was a Cape Verde hurricane originating from a tropical wave on September 16 in the eastern Atlantic Ocean. After remaining a weak tropical cyclone for several days, Gloria intensified into a hurricane on September 22 north of the Lesser Antilles. During that time, the storm had moved generally westward, although it turned to the northwest due to a weakening of the ridge. Gloria quickly intensified on September 24, and the next day reached peak winds of 145 mph (233 km/h). The hurricane weakened before striking the Outer Banks of North Carolina on September 27. Later that day, Gloria made two subsequent landfalls on Long Island and across the coastline of western Connecticut, before becoming extratropical on September 28 over New England. The remnants moved through Atlantic Canada and went on to impact Western Europe, eventually dissipating on October 4.

Before Gloria made landfall, the National Hurricane Center issued hurricane warnings at some point for the East Coast of the United States from South Carolina to Maine. Hundreds of thousands of people evacuated, and the hurricane was described as the "storm of the century." In general, Gloria's strongest winds remained east of the center, which largely spared locations from North Carolina to New Jersey, and the passage at low tide reduced storm surge. Hurricane-force winds and gusts affected much of the path, which knocked down trees and power lines. This left over 4 million people without power, causing the worst power outage in Connecticut history related to a natural disaster. Fallen trees caused six of the storm's fourteen deaths. (Full article...)

The Ediacaran ( /ˌiːdiˈækərən, ˌɛdi-/ EE-dee-AK-ər-ən, ED-ee-) is a geological period of the Neoproterozoic Era that spans 96 million years from the end of the Cryogenian Period at 635 Mya to the beginning of the Cambrian Period at 538.8 Mya. It is the last period of the Proterozoic Eon as well as the last of the so-called "Precambrian supereon", before the beginning of the subsequent Cambrian Period marks the start of the Phanerozoic Eon, where recognizable fossil evidence of life becomes common.

The Ediacaran Period is named after the Ediacara Hills of South Australia, where trace fossils of a diverse community of previously unrecognized lifeforms (later named the Ediacaran biota) were first discovered by geologist Reg Sprigg in 1946. Its status as an official geological period was ratified in 2004 by the International Union of Geological Sciences (IUGS), making it the first new geological period declared in 120 years. Although the period took namesake from the Ediacara Hills in the Nilpena Ediacara National Park, the type section is actually located in the bed of the Enorama Creek within the Brachina Gorge in the Ikara-Flinders Ranges National Park, at , approximately 55 km (34 mi) southeast of the Ediacara Hills fossil site. (Full article...)

The Cretaceous–Paleogene (K–Pg) extinction event, formerly known as the Cretaceous-Tertiary (K–T) extinction event, was the mass extinction of three-quarters of the plant and animal species on Earth approximately 66 million years ago. The event caused the extinction of all non-avian dinosaurs. Most other tetrapods weighing more than 25 kg (55 lb) also became extinct, with the exception of some ectothermic species such as sea turtles and crocodilians. It marked the end of the Cretaceous period, and with it the Mesozoic era, while heralding the beginning of the current geological era, the Cenozoic Era. In the geologic record, the K–Pg event is marked by a thin layer of sediment called the K–Pg boundary or K–T boundary, which can be found throughout the world in marine and terrestrial rocks. The boundary clay shows unusually high levels of the metal iridium, which is more common in asteroids than in the Earth's crust.

As originally proposed in 1980 by a team of scientists led by Luis Alvarez and his son Walter, it is now generally thought that the K–Pg extinction was caused by the impact of a massive asteroid 10 to 15 km (6 to 9 mi) wide, 66 million years ago causing the Chicxulub impact crater, which devastated the global environment, mainly through a lingering impact winter which halted photosynthesis in plants and plankton. The impact hypothesis, also known as the Alvarez hypothesis, was bolstered by the discovery of the 180 km (112 mi) Chicxulub crater in the Gulf of Mexico's Yucatán Peninsula in the early 1990s, which provided conclusive evidence that the K–Pg boundary clay represented debris from an asteroid impact. The fact that the extinctions occurred simultaneously provides strong evidence that they were caused by the asteroid. A 2016 drilling project into the Chicxulub peak ring confirmed that the peak ring comprised granite ejected within minutes from deep in the earth, but contained hardly any gypsum, the usual sulfate-containing sea floor rock in the region: the gypsum would have vaporized and dispersed as an aerosol into the atmosphere, causing longer-term effects on the climate and food chain. In October 2019, researchers asserted that the event rapidly acidified the oceans and produced long-lasting effects on the climate, detailing the mechanisms of the mass extinction. (Full article...)

Calabozos is a Holocene caldera in central Chile's Maule Region (7th Region). Part of the Chilean Andes' volcanic segment, it is considered a member of the Southern Volcanic Zone (SVZ), one of the three distinct volcanic belts of South America. This most active section of the Andes runs along central Chile's western edge, and includes more than 70 of Chile's stratovolcanoes and volcanic fields. Calabozos lies in an extremely remote area of poorly glaciated mountains.

Calabozos and the majority of the Andean volcanoes formed from the subduction of the oceanic Nazca Plate under the continental South American continental lithosphere. The caldera is in a transitional region between thick and thin lithosphere, and is probably supplied by a pool of andesitic and rhyolitic magma. It sits on a historic bed of volcanic and plutonic sedimentary rock (rock formed within the Earth) that in turn sits on top of a layer of merged sedimentary and metamorphic rock. (Full article...)

The 2002 Bou'in-Zahra earthquake (also known as the 2002 Avaj earthquake or the 2002 Changureh earthquake) occurred on 22 June 2002. The epicenter was near the city of Bou'in-Zahra in Qazvin province, a region of northwestern Iran which is crossed by several major faults that is known for destructive earthquakes. The shock measured 6.5 on the M_wc scale, had a maximum Mercalli intensity of VIII (Severe), and was followed by more than 20 aftershocks. At least 261 people were killed and 1,500 more were injured.

According to the International Institute of Earthquake Engineering and Seismology (IIEES), the earthquake was felt as far away as the capital city of Tehran, approximately 290 kilometres (180 mi) east of the epicenter, although no damage was reported there. Most houses in the region were single-story masonry buildings, and virtually all of these collapsed. The public became angry due to the slow official response to victims who needed supplies. Residents of the town of Avaj resorted to throwing stones at the car of a government minister. (Full article...)

Crater Lake (Klamath: Giiwas) is a volcanic crater lake in south-central Oregon in the Western United States. It is the main feature of Crater Lake National Park and is a tourist attraction for its deep blue color and water clarity. The lake partly fills a 2,148-foot-deep (655 m) caldera that was formed around 7,700 (± 150) years ago
by the collapse of the volcano Mount Mazama. No rivers flow into or out of the lake; the evaporation is compensated for by rain and snowfall at a rate such that the total amount of water is replaced every 150 years. With a depth of 1,949 feet (594 m), the lake is the deepest in the United States. In the world, it ranks eleventh for maximum depth, as well as fifth for mean depth.

Crater Lake features two small islands. Wizard Island, located near the western shore of the lake, is a cinder cone about 316 acres (128 hectares) in size. Phantom Ship, a natural rock pillar, is located near the southern shore. (Full article...)

and
Earth is the third planet from the Sun and the only astronomical object known to harbor life. This is enabled by Earth being an ocean world, the only one in the Solar System sustaining liquid surface water. Almost all of Earth's water is contained in its global ocean, covering 70.8% of Earth's crust. The remaining 29.2% of Earth's crust is land, most of which is located in the form of continental landmasses within Earth's land hemisphere. Most of Earth's land is at least somewhat humid and covered by vegetation, while large sheets of ice at Earth's polar deserts retain more water than Earth's groundwater, lakes, rivers, and atmospheric water combined. Earth's crust consists of slowly moving tectonic plates, which interact to produce mountain ranges, volcanoes, and earthquakes. Earth has a liquid outer core that generates a magnetosphere capable of deflecting most of the destructive solar winds and cosmic radiation.

Earth has a dynamic atmosphere, which sustains Earth's surface conditions and protects it from most meteoroids and UV-light at entry. It has a composition of primarily nitrogen and oxygen. Water vapor is widely present in the atmosphere, forming clouds that cover most of the planet. The water vapor acts as a greenhouse gas and, together with other greenhouse gases in the atmosphere, particularly carbon dioxide (CO₂), creates the conditions for both liquid surface water and water vapor to persist via the capturing of energy from the Sun's light. This process maintains the current average surface temperature of 14.76 °C (58.57 °F), at which water is liquid under normal atmospheric pressure. Differences in the amount of captured energy between geographic regions (as with the equatorial region receiving more sunlight than the polar regions) drive atmospheric and ocean currents, producing a global climate system with different climate regions, and a range of weather phenomena such as precipitation, allowing components such as nitrogen to cycle. (Full article...)

The geology of solar terrestrial planets mainly deals with the geological aspects of the four terrestrial planets of the Solar System – Mercury, Venus, Earth, and Mars – and one terrestrial dwarf planet: Ceres. Earth is the only terrestrial planet known to have an active hydrosphere.

Terrestrial planets are substantially different from the giant planets, which might not have solid surfaces and are composed mostly of some combination of hydrogen, helium, and water existing in various physical states. Terrestrial planets have a compact, rocky surfaces, and Venus, Earth, and Mars each also has an atmosphere. Their size, radius, and density are all similar. (Full article...)

The 1949 Ambato earthquake was a magnitude 6.4 M_s earthquake that on August 5, 1949, struck Ecuador's Tungurahua Province southeast of its capital Ambato and killed 5,050 people. The nearby villages of Guano, Patate, Pelileo, and Pillaro were destroyed, and the city of Ambato suffered heavy damage. The earthquake flattened buildings and subsequent landslides caused damage throughout the Tungurahua, Chimborazo, and Cotopaxi Provinces. It disrupted water mains and communication lines and opened a fissure into which the small town of Libertad sank. Moderate shaking from the event extended as far away as Quito and Guayaquil.

Earthquakes in Ecuador stem from two major interrelated tectonic areas: the subduction of the Nazca plate under the South American plate and the Andean Volcanic Belt. The 1949 Ambato earthquake initially followed an intersection of several northwest–southeast-trending faults in the Inter-Andean Valley which were created by the subduction of the Carnegie Ridge. Strata of rock cracked as the earthquake ruptured the faults, sending out powerful shock waves. Today threats exist throughout the country from both interplate and intraplate seismicity. (Full article...)

The climate of India consists of a wide range of weather conditions across a vast geographic scale and varied topography. Based on the Köppen system, India encompasses a diverse array of climatic subtypes. These range from arid and semi-arid regions in the west to highland, sub-arctic, tundra, and ice cap climates in the northern Himalayan regions, varying with elevation.

The northern lowlands experience subtropical conditions which become more temperate at higher altitudes, like the Sivalik Hills, or continental in some areas like Gulmarg. In contrast, much of the south and the east exhibit tropical climate conditions, which support lush rainforests in parts of these territories. Many regions have starkly different microclimates, making it one of the most climatically diverse countries in the world. The country's meteorological department follows four seasons with some local adjustments: winter (December to February), summer (March to May), monsoon or south-west monsoon (June to September) and post-monsoon or north-east monsoon (October to November). Some parts of the country with subtropical, temperate or continental climates also experience spring and autumn. (Full article...)

Radiocarbon dating (also referred to as carbon dating or carbon-14 dating) is a method for determining the age of an object containing organic material by using the properties of radiocarbon, a radioactive isotope of carbon.

The method was developed in the late 1940s at the University of Chicago by Willard Libby. It is based on the fact that radiocarbon (¹⁴
C) is constantly being created in the Earth's atmosphere by the interaction of cosmic rays with atmospheric nitrogen. The resulting ¹⁴
C combines with atmospheric oxygen to form radioactive carbon dioxide, which is incorporated into plants by photosynthesis; animals then acquire ¹⁴
C by eating the plants. When the animal or plant dies, it stops exchanging carbon with its environment, and thereafter the amount of ¹⁴
C it contains begins to decrease as the ¹⁴
C undergoes radioactive decay. Measuring the amount of ¹⁴
C in a sample from a dead plant or animal, such as a piece of wood or a fragment of bone, provides information that can be used to calculate when the animal or plant died. The older a sample is, the less ¹⁴
C there is to be detected, and because the half-life of ¹⁴
C (the period of time after which half of a given sample will have decayed) is about 5,730 years, the oldest dates that can be reliably measured by this process date to approximately 50,000 years ago, although special preparation methods occasionally make an accurate analysis of older samples possible. Libby received the Nobel Prize in Chemistry for his work in 1960. (Full article...)

Hurricane Lili was the second costliest, deadliest, and most intense hurricane of the 2002 Atlantic hurricane season, only surpassed by Hurricane Isidore, which affected the same areas around a week before Lili. Lili was the twelfth named storm, fourth hurricane, and second major hurricane of the 2002 Atlantic hurricane season. The storm developed from a tropical disturbance in the open Atlantic on September 21. It continued westward, affecting the Lesser Antilles as a tropical storm, then entered the Caribbean. As it moved west, the storm dissipated while being affected by wind shear south of Cuba, and regenerated when the vertical wind shear weakened. It turned to the northwest and strengthened up to category 2 strength on October 1. Lili made two landfalls in western Cuba later that day, and then entered the Gulf of Mexico. The hurricane rapidly strengthened on October 2, reaching Category 4 strength that afternoon. It weakened rapidly thereafter, and hit Louisiana as a Category 1 hurricane on October 3. It moved inland and dissipated on October 6.

Lili caused extensive damage through the Caribbean, particularly to crops and poorly built homes. Mudslides were common on the more mountainous islands, particularly Haiti and Jamaica. In the United States, the storm cut off the production of oil within the Gulf of Mexico, and caused severe damage in parts of Louisiana. Lili was also responsible for severe damage to the barrier islands and marshes in the southern portion of the state. Total damage amounted to $925 million (2002 USD), and the storm killed 15 people during its existence. (Full article...)

Ice drilling allows scientists studying glaciers and ice sheets to gain access to what is beneath the ice, to take measurements along the interior of the ice, and to retrieve samples. Instruments can be placed in the drilled holes to record temperature, pressure, speed, direction of movement, and for other scientific research, such as neutrino detection.

Many different methods have been used since 1840, when the first scientific ice drilling expedition attempted to drill through the Unteraargletscher in the Alps. Two early methods were percussion, in which the ice is fractured and pulverized, and rotary drilling, a method often used in mineral exploration for rock drilling. In the 1940s, thermal drills began to be used; these drills melt the ice by heating the drill. Drills that use jets of hot water or steam to bore through ice soon followed. A growing interest in ice cores, used for palaeoclimatological research, led to ice coring drills being developed in the 1950s and 1960s, and there are now many different coring drills in use. For obtaining ice cores from deep holes, most investigators use cable-suspended electromechanical drills, which use an armoured cable to carry electrical power to a mechanical drill at the bottom of the borehole. (Full article...)

Bryce Canyon National Park (/braɪs/) is a national park of the United States located in southwestern Utah. The major feature of the park is Bryce Canyon, which despite its name, is not a canyon, but a collection of giant natural amphitheaters along the eastern side of the Paunsaugunt Plateau. Bryce is distinctive due to geological structures called hoodoos, formed by frost weathering and stream erosion of the river and lake bed sedimentary rock. The red, orange, and white colors of the rocks provide spectacular views for park visitors. Bryce Canyon National Park is much smaller and sits at a much higher elevation than nearby Zion National Park. The rim at Bryce varies from 8,000 to 9,000 feet (2,400 to 2,700 m).

The area is in portions of Garfield County and Kane County. (Full article...)

Yosemite National Park (/joʊˈsɛmɪti/ yoh-SEM-ih-tee) is a national park of the United States in California. It is bordered on the southeast by Sierra National Forest and on the northwest by Stanislaus National Forest. The park is managed by the National Park Service and covers 759,620 acres (1,187 sq mi; 3,074 km²) in four counties – centered in Tuolumne and Mariposa, extending north and east to Mono and south to Madera. Designated a World Heritage Site in 1984, Yosemite is internationally recognized for its granite cliffs, waterfalls, clear streams, groves of giant sequoia, lakes, mountains, meadows, glaciers, and biological diversity. Almost 95 percent of the park is designated wilderness. Yosemite is one of the largest and least fragmented habitat blocks in the Sierra Nevada mountain range.

Its geology is characterized by granite and remnants of older rock. About 10 million years ago, the Sierra Nevada was uplifted and tilted to form its unique slopes, which increased the steepness of stream and river beds, forming deep, narrow canyons. About one million years ago glaciers formed at higher elevations. They moved downslope, cutting and sculpting the U-shaped Yosemite Valley. (Full article...)