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Lake Atna
Lake Atna (; also known as Lake Ahtna) was a prehistoric proglacial lake that initially formed approximately 58 ka (thousand years ago) in the Copper River Basin, an area roughly centered around northeast of modern-day Anchorage, Alaska. The lake formed, and dispersed, during the Wisconsin glaciation. The lake existed in several forms, with several prominent shorelines observable in modern geology. At its greatest extent, the lake surface area was approximately half the size of modern-day Lake Ontario, and possibly much larger. The basin of the lake lay within an area bordered by the Alaska Range to the north, the Wrangell Mountains to the east, the Chugach Mountains to the south, and the Talkeetna Mountains to the west. Lake Atna may have generated several of the largest ever glacial lake outburst floods. Old deposits from one of these floods may have added to the destruction caused by the 1964 Alaska earthquake. Discovery In 1898, Frank Charles Schrader undertook a stud ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Southcentral Alaska
Southcentral Alaska (russian: Юго-Центральная Аляска) is the portion of the U.S. state of Alaska consisting of the shorelines and uplands of the central Gulf of Alaska. Most of the population of the state lives in this region, concentrated in and around the city of Anchorage, Alaska, Anchorage. The area includes Cook Inlet, the Matanuska-Susitna Valley, the Kenai Peninsula, Prince William Sound, and the Copper River (Alaska), Copper River Valley. Tourism, fisheries, and petroleum production are important economic activities. Cities The major city is Anchorage, Alaska, Anchorage. Other major towns include Palmer, Alaska, Palmer, Wasilla, Alaska, Wasilla, Kenai, Alaska, Kenai, Soldotna, Alaska, Soldotna, Homer, Alaska, Homer, Seward, Alaska, Seward, Valdez, Alaska, Valdez, and Cordova, Alaska, Cordova. Climate The climate of Southcentral Alaska is subarctic climate, subarctic. Temperatures range from an average high of in July to an average low of in Dece ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1964 Alaska Earthquake
The 1964 Alaskan earthquake, also known as the Great Alaskan earthquake and Good Friday earthquake, occurred at 5:36 PM AKST on Good Friday, March 27.US Geological Survey report on the earthquake Across south-central , ground fissures, collapsing structures, and s resulting from the earthquake caused about 131 deaths. Lasting four minutes and thirty-eight seconds, the magnitude 9.2 |
Pygmy Whitefish
The pygmy whitefish (''Prosopium coulterii'') is a freshwater whitefish of the genus ''Prosopium'' in the family Salmonidae. Found in the mountain streams and lakes in western North America, it also has isolated populations in Lake Superior and in Ekityki Lake, Chukchi Peninsula. Description The pygmy whitefish is a small herring-like fish with a long and cylindrical body by comparison to other whitefishes. Silvery in colour, it has a brownish back, and a whitish belly.Becker, 1983, pp. 369–371 Black spots on the side called "parr marks", which are present on young trout or "parrs", are present on the young of this species, and on adults in some Alaskan populations. Commonly ranging from in length, it is typically long, and reaches a maximum length of .Froese and Pauly, 2010 It is identified by its small size, and its large eye, which has a greater length than its blunt snout.Page and Burr, 1991, pp. 45–46 Its dorsal fin and pectoral fin are usually clear, and its tail is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alaska Department Of Fish And Game
The Alaska Department of Fish and Game (ADF&G) is a department within the government of Alaska. ADF&G's mission is to protect, maintain, and improve the fish, game, and aquatic plant resources of the state, and manage their use and development in the best interest of the economy and the well-being of the people of the state, consistent with the sustained yield principle. ADF&G manages approximately 750 active fisheries, 26 game management units, and 32 special areas. From resource policy to public education, the department considers public involvement essential to its mission and goals. The department is committed to working with tribes in Alaska and with a diverse group of State and Federal agencies. The department works cooperatively with various universities and nongovernmental organizations in formal and informal partnership arrangements, and assists local research or baseline environmental monitoring through citizen science programs. History In 1949, the Territorial Legislatu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bureau Of Land Management
The Bureau of Land Management (BLM) is an agency within the United States Department of the Interior responsible for administering federal lands. Headquartered in Washington DC, and with oversight over , it governs one eighth of the country's landmass. President Harry S. Truman created the BLM in 1946 by combining two existing agencies: the General Land Office and the Grazing Service. The agency manages the federal government's nearly of subsurface mineral estate located beneath federal, state and private lands severed from their surface rights by the Homestead Act of 1862. Most BLM public lands are located in these 12 western states: Alaska, Arizona, California, Colorado, Idaho, Montana, Nevada, New Mexico, Oregon, Utah, Washington and Wyoming. The mission of the BLM is "to sustain the health, diversity, and productivity of the public lands for the use and enjoyment of present and future generations." Originally BLM holdings were described as "land nobody wanted" because home ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isostasy
Isostasy (Greek ''ísos'' "equal", ''stásis'' "standstill") or isostatic equilibrium is the state of gravitational equilibrium between Earth's crust (or lithosphere) and mantle such that the crust "floats" at an elevation that depends on its thickness and density. This concept is invoked to explain how different topographic heights can exist at Earth's surface. Although originally defined in terms of continental crust and mantle, it has subsequently been interpreted in terms of lithosphere and asthenosphere, particularly with respect to oceanic island volcanoes, such as the Hawaiian Islands. Although Earth is a dynamic system that responds to loads in many different ways, isostasy describes the important limiting case in which crust and mantle are in static equilibrium. Certain areas (such as the Himalayas and other convergent margins) are not in isostatic equilibrium and are not well described by isostatic models. The general term 'isostasy' was coined in 1882 by the Ameri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
High Water Mark
A high water mark is a point that represents the maximum rise of a body of water over land. Such a mark is often the result of a flood, but high water marks may reflect an all-time high, an annual high (highest level to which water rose that year) or the high point for some other division of time. Knowledge of the high water mark for an area is useful in managing the development of that area, particularly in making preparations for flood surges. High water marks from floods have been measured for planning purposes since at least as far back as the civilizations of ancient Egypt. It is a common practice to create a physical marker indicating one or more of the highest water marks for an area, usually with a line at the level to which the water rose, and a notation of the date on which this high water mark was set. This may be a free-standing flood level sign or other marker, or it may be affixed to a building or other structure that was standing at the time of the flood that se ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spruce
A spruce is a tree of the genus ''Picea'' (), a genus of about 35 species of coniferous evergreen trees in the family Pinaceae, found in the northern temperate and boreal (taiga) regions of the Earth. ''Picea'' is the sole genus in the subfamily Piceoideae. Spruces are large trees, from about 20 to 60 m (about 60–200 ft) tall when mature, and have whorled branches and conical form. They can be distinguished from other members of the pine family by their needles (leaves), which are four-sided and attached singly to small persistent peg-like structures (pulvini or sterigmata) on the branches, and by their cones (without any protruding bracts), which hang downwards after they are pollinated. The needles are shed when 4–10 years old, leaving the branches rough with the retained pegs. In other similar genera, the branches are fairly smooth. Spruce are used as food plants by the larvae of some Lepidoptera (moth and butterfly) species, such as the eastern spruce budwo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Miocene
The Miocene ( ) is the first geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and means "less recent" because it has 18% fewer modern marine invertebrates than the Pliocene has. The Miocene is preceded by the Oligocene and is followed by the Pliocene. As Earth went from the Oligocene through the Miocene and into the Pliocene, the climate slowly cooled towards a series of ice ages. The Miocene boundaries are not marked by a single distinct global event but consist rather of regionally defined boundaries between the warmer Oligocene and the cooler Pliocene Epoch. During the Early Miocene, the Arabian Peninsula collided with Eurasia, severing the connection between the Mediterranean and Indian Ocean, and allowing a faunal interchange to occur between Eurasia and Africa, including the dispersal of proboscideans into Eurasia. During the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pleistocene
The Pleistocene ( , often referred to as the ''Ice age'') is the geological Epoch (geology), epoch that lasted from about 2,580,000 to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was finally confirmed in 2009 by the International Union of Geological Sciences, the cutoff of the Pleistocene and the preceding Pliocene was regarded as being 1.806 million years Before Present (BP). Publications from earlier years may use either definition of the period. The end of the Pleistocene corresponds with the end of the last glacial period and also with the end of the Paleolithic age used in archaeology. The name is a combination of Ancient Greek grc, label=none, πλεῖστος, pleīstos, most and grc, label=none, καινός, kainós (latinized as ), 'new'. At the end of the preceding Pliocene, the previously isolated North and South American continents were joined by the Isthmus of Panama, causing Great American Interchang ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
