![]() Paoha Island viewed from Mono Lake Visitor Center | |
Geography | |
---|---|
Location | Mono County, California, United States |
Coordinates | 38°00′01″N119°00′57″W / 38.0002°N 119.0157°W |
Total islands | 1 |
Area | 3.5 sq mi (9.1 km2) |
Length | 2 mi (3 km) |
Width | 1.5 mi (2.4 km) |
Highest elevation | 6,670 ft (2033 m) |
Administration | |
United States | |
Demographics | |
Population | Uninhabited |
Paoha Island is a volcanic island in Mono Lake, an endorheic lake in the U.S. state of California. [1] The island was formed by a series of eruptions in the 17th century. It is composed of lakebed sediments deposited above volcanic domes. It is one of two major islands in the lake, the other being the smaller Negit Island. Its name comes from a Native American word, Pa-o-ha, describing the abundant hot springs and fumaroles on its surface.
Before the mid-17th century, the present-day Paoha Island did not exist. [2] Volcanic eruptions on the lakebed gave rise to the island, which eventually rose to 6,670 feet (2,030 m) above sea level, 290 feet (88 m) above the present-day elevation of Mono Lake. The pale color of the island is attributed to lakebed sediments rising above the lake surface along with the volcanic material. [2]
The volcanic origin of the island gave rise to many vents, hot springs, fumaroles and mudpots on the surface of the island. An eruption sometime before the twentieth century created a crater lake that is shaped like a heart. Paoha Island is the younger of the two Mono Lake islands; Negit rose about 1,350 years before Paoha. [3]
Paoha Island was named by Israel Cook Russell, a well-known American geologist, in the late 19th century. [4] It supposedly received its name from the Paiute word pa-o-ha, for spirits they believed to exist in Paoha Island's hot springs. These spirits, or elves, were described as "diminutive sprites having long, waving hair, that were sometimes seen in the vapor-wreaths escaping from the hot springs." [5]
The surface sediments of Paoha Island consist primarily of clay and marl, which are responsible for the pale surface. Volcanic ash is scattered all around the island and basalt is exposed at some of the lower elevations. There are also river-deposited sediments and granite rocks. [6]
In his semi-autobiographical book Roughing It , writer Mark Twain recounted a "voyage of discovery" to the island while camping on the shores of Mono Lake. [7] He and a companion had been led to believe that on the island "within ten feet of the boiling spring is a spring of pure cold water, sweet and pure," but once there they "found nothing but solitude, ashes, and heartbreaking silence"—and they had already emptied their canteens. [7] Meanwhile, their untethered rowboat began to drift away. Marooned, they would have died of thirst and starvation: it was a twelve-mile [8] swim back to shore and "that venomous [lake] water would eat a man's eyes out like fire, and burn him out inside too, if he shipped a sea." [7] As the wind of a rising storm blew the rowboat past an island cape, Twain's companion managed to jump aboard and recover it. [7]
Paoha Island is located in the central part of Mono Lake, slightly closer to the western shore. It is a roughly oval-shaped landmass 2 miles (3.2 km) north-south and 1.5 miles (2.4 km) east-west. It is separated from Negit Island, to the north-northwest, by a narrow channel. During low water levels, Negit Island and eventually Paoha Island become connected to the mainland in one giant peninsula.
The island is more mountainous near the east side, with the highest volcanic domes rising more or less than 200 feet (61 m) above the lake surface. The highest cone, which contains the heart-shaped crater lake, is located at the far northeastern end of the island. Several small islets are located off the island's west and south shores.
Mono Lake is a saline soda lake in Mono County, California, formed at least 760,000 years ago as a terminal lake in an endorheic basin. The lack of an outlet causes high levels of salts to accumulate in the lake which make its water alkaline.
Long Valley Caldera is a depression in eastern California that is adjacent to Mammoth Mountain. The valley is one of the Earth's largest calderas, measuring about 20 mi (32 km) long (east-west), 11 mi (18 km) wide (north-south), and up to 3,000 ft (910 m) deep.
A fumarole is a vent in the surface of the Earth or other rocky planets from which hot volcanic gases and vapors are emitted, without any accompanying liquids or solids. Fumaroles are characteristic of the late stages of volcanic activity, but fumarole activity can also precede a volcanic eruption and has been used for eruption prediction. Most fumaroles die down within a few days or weeks of the end of an eruption, but a few are persistent, lasting for decades or longer. An area containing fumaroles is known as a fumarole field.
Mount Shasta is a potentially active volcano at the southern end of the Cascade Range in Siskiyou County, California. At an elevation of 14,179 feet, it is the second-highest peak in the Cascades and the fifth-highest in the state. Mount Shasta has an estimated volume of 85 cubic miles, which makes it the most voluminous stratovolcano in the Cascade Volcanic Arc. The mountain and surrounding area are part of the Shasta–Trinity National Forest.
Crater Lake 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 famous 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 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 250 years. With a depth of 1,949 feet (594 m), the lake is the deepest in the United States. In the world, it ranks tenth for maximum depth, as well as third for mean (average) depth.
Crater Lake National Park is an American national park located in southern Oregon. Established in 1902, Crater Lake is the fifth-oldest national park in the United States and the only national park in Oregon. The park encompasses the caldera of Crater Lake, a remnant of Mount Mazama, a destroyed volcano, and the surrounding hills and forests.
The geothermal areas of Yellowstone include several geyser basins in Yellowstone National Park as well as other geothermal features such as hot springs, mud pots, and fumaroles. The number of thermal features in Yellowstone is estimated at 10,000. A study that was completed in 2011 found that a total of 1,283 geysers have erupted in Yellowstone, 465 of which are active during an average year. These are distributed among nine geyser basins, with a few geysers found in smaller thermal areas throughout the Park. The number of geysers in each geyser basin are as follows: Upper Geyser Basin (410), Midway Geyser Basin (59), Lower Geyser Basin (283), Norris Geyser Basin (193), West Thumb Geyser Basin (84), Gibbon Geyser Basin (24), Lone Star Geyser Basin (21), Shoshone Geyser Basin (107), Heart Lake Geyser Basin (69), other areas (33). Although famous large geysers like Old Faithful are part of the total, most of Yellowstone's geysers are small, erupting to only a foot or two. The hydrothermal system that supplies the geysers with hot water sits within an ancient active caldera. Many of the thermal features in Yellowstone build up sinter, geyserite, or travertine deposits around and within them.
Mammoth Mountain is a lava dome complex partially located within the town of Mammoth Lakes, California, in the Inyo National Forest of Madera and Mono Counties. It is home to a large ski area primarily on the Mono County side.
Landforms are categorized by characteristic physical attributes such as their creating process, shape, elevation, slope, orientation, rock exposure, and soil type.
The Mono–Inyo Craters are a volcanic chain of craters, domes and lava flows in Mono County, Eastern California. The chain stretches 25 miles (40 km) from the northwest shore of Mono Lake to the south of Mammoth Mountain. The Mono Lake Volcanic Field forms the northernmost part of the chain and consists of two volcanic islands in the lake and one cinder cone volcano on its northwest shore. Most of the Mono Craters, which make up the bulk of the northern part of the Mono–Inyo chain, are phreatic volcanoes that have since been either plugged or over-topped by rhyolite domes and lava flows. The Inyo volcanic chain form much of the southern part of the chain and consist of phreatic explosion pits, and rhyolitic lava flows and domes. The southernmost part of the chain consists of fumaroles and explosion pits on Mammoth Mountain and a set of cinder cones south of the mountain; the latter are called the Red Cones.
The Lassen volcanic area presents a geological record of sedimentation and volcanic activity in and around Lassen Volcanic National Park in Northern California, U.S. The park is located in the southernmost part of the Cascade Mountain Range in the Pacific Northwest region of the United States. Pacific Oceanic tectonic plates have plunged below the North American Plate in this part of North America for hundreds of millions of years. Heat and molten rock from these subducting plates has fed scores of volcanoes in California, Oregon, Washington and British Columbia over at least the past 30 million years, including these in the Lassen volcanic areas.
Kilbourne Hole is a maar volcanic crater, located 30 miles (48 km) west of the Franklin Mountains of El Paso, Texas, in the Potrillo volcanic field of Doña Ana County, New Mexico. Another maar, Hunt's Hole, lies just two miles (3.2 km) south. Kilbourne Hole is notable for the large number of mantle xenoliths that were carried to the surface by the eruption.
Mount Mazama is a complex volcano in the western U.S. state of Oregon, in a segment of the Cascade Volcanic Arc and Cascade Range. Most of the mountain collapsed following a major eruption approximately 7,700 years ago. The volcano is in Klamath County, in the southern Cascades, 60 miles (97 km) north of the Oregon–California border. Its collapse, due to the eruption of magma emptying the underlying magma chamber, formed a caldera that holds Crater Lake. The mountain is in Crater Lake National Park. Mount Mazama originally had an elevation of 12,000 feet (3,700 m), but following its climactic eruption this was reduced to 8,157 feet (2,486 m). Crater Lake is 1,943 feet (592 m) deep, the deepest freshwater body in the U.S. and the second deepest in North America after Great Slave Lake in Canada.
Mount Katmai is a large active stratovolcano on the Alaska Peninsula in southern Alaska, located within Katmai National Park and Preserve. It is about 6.3 miles (10 km) in diameter with a central lake-filled caldera about two by three miles in size, formed during the Novarupta eruption of 1912. The caldera rim reaches a maximum elevation of 6,716 feet (2,047 m). In 1975 the surface of the crater lake was at an elevation of about 4,220 feet (1,286 m), and the estimated elevation of the caldera floor is about 3,400 ft (1,040 m). The mountain is located in Kodiak Island Borough, very close to its border with Lake and Peninsula Borough. The volcano has caused ten known fatalities due to gas exposure.
Ubehebe Crater is a large volcanic crater of the Ubehebe Craters volcanic field in the northern half of Death Valley, in Death Valley National Park, California, United States.
The Mono Basin is an endorheic drainage basin located east of Yosemite National Park in California and Nevada. It is bordered to the west by the Sierra Nevada, to the east by the Cowtrack Mountains, to the north by the Bodie Hills, and to the south by the north ridge of the Long Valley Caldera.
Panum Crater is a volcanic cone that is part of the Mono–Inyo Craters, a chain of recent volcanic cones south of Mono Lake and east of the Sierra Nevada, in California, United States. Panum Crater is between 600 and 700 years old, and it exhibits all of the characteristics of the textbook rhyolitic lava dome.
Blue Lake Crater is a maar, or a broad, low-relief volcanic crater, in the U.S. state of Oregon. Located in Jefferson County, it consists of three overlapping craters, which hold Blue Lake. The drainage basin for Blue Lake has very steep, forested slopes and is mostly part of the explosion crater left by the volcano's eruption. The volcano lies within the Metolius River basin, which supports a wide array of plant life, large and small mammals, and more than 80 bird species. A 2009 Oregon law designated the Metolius River basin as an area of critical concern, preventing large-scale development and protecting wildlife.
Hot Creek, starting as Mammoth Creek, is a stream in Mono County of eastern California, in the Western United States. It is within the Inyo National Forest.
Hydrothermal explosions occur when superheated water trapped below the surface of the Earth rapidly converts from liquid to steam, violently disrupting the confining rock. Boiling water, steam, mud, and rock fragments are ejected over an area of a few meters up to several kilometers in diameter. Although the energy originally comes from a deep igneous source, this energy is transferred to the surface by circulating meteoric water or mixtures of meteoric and magmatic water rather than by magma, as occurs in volcanic eruptions. The energy is stored as heat in hot water and rock within a few hundred feet of the surface.