Basalt is a common extrusive igneous rock formed from the rapid cooling of basaltic lava exposed at or very near the surface of a planet or moon. Flood basalt describes the formation in a series of basalt flows. By definition, basalt is an igneous rock with generally 45-55% silica and less than 10% feldspathoid by volume. Basalt commonly features a very fine-grained or glassy matrix interspersed with visible mineral grains, the average density is 3.0 gm/cm3. Basalt is defined by its content and texture, and physical descriptions without mineralogical context may be unreliable in some circumstances. Basalt is usually grey to black in colour, but rapidly weathers to brown or rust-red due to oxidation of its mafic minerals into hematite, although usually characterized as dark, basaltic rocks exhibit a wide range of shading due to regional geochemical processes. Due to weathering or high concentrations of plagioclase, some basalts can be quite light-coloured and these phenocrysts usually are of olivine or a calcium-rich plagioclase, which have the highest melting temperatures of the typical minerals that can crystallize from the melt.
Basalt with a texture is called vesicular basalt, when the bulk of the rock is mostly solid. Gabbro is often marketed commercially as black granite and these ultramafic volcanic rocks, with silica contents below 45% are usually classified as komatiites. Agricola applied basalt to the black rock of the Schloßberg at Stolpen. Tholeiitic basalt is relatively rich in silica and poor in sodium, included in this category are most basalts of the ocean floor, most large oceanic islands, and continental flood basalts such as the Columbia River Plateau. Basalt rocks are in some cases classified after their content in High-Ti and Low-Ti varieties. High-Ti and Low-Ti basalts have been distinguished in the Paraná and Etendeka traps and it has greater than 17% alumina and is intermediate in composition between tholeiite and alkali basalt, the relatively alumina-rich composition is based on rocks without phenocrysts of plagioclase. Alkali basalt is relatively poor in silica and rich in sodium and it is silica-undersaturated and may contain feldspathoids, alkali feldspar and phlogopite.
Boninite is a form of basalt that is erupted generally in back-arc basins. Ocean island basalt Lunar basalt On Earth, most basalt magmas have formed by melting of the mantle. Basalt commonly erupts on Io, the third largest moon of Jupiter, and has formed on the Moon, Venus. The crustal portions of oceanic tectonic plates are composed predominantly of basalt, produced from upwelling mantle below, the mineralogy of basalt is characterized by a preponderance of calcic plagioclase feldspar and pyroxene
Severe weather refers to any dangerous meteorological phenomena with the potential to cause damage, serious social disruption, or loss of human life. Types of severe weather phenomena vary, depending on the latitude, topography and seasonal severe weather phenomena include blizzards, ice storms, and duststorms. Meteorologists generally define severe weather as any aspect of the weather that poses risks to life, a narrower definition of severe weather is any weather phenomena relating to severe thunderstorms. According to the World Meteorological Organization, severe weather can be categorized into two groups, general severe weather and localized severe weather, European wind storms, and the phenomena that accompany them form over wide geographic areas. These occurrences are classified as severe weather. Downbursts and tornadoes are more localized and therefore have a limited geographic effect. These forms of weather are classified as localized severe weather, the term severe weather is technically not the same phenomenon as extreme weather.
Extreme weather describes unusual weather events that are at the extremes of the distribution for a given area. Organized severe weather occurs from the conditions that generate ordinary thunderstorms, atmospheric moisture, lift. A wide variety of conditions cause severe weather, several factors can convert thunderstorms into severe weather. For example, a pool of air aloft may aid in the development of large hail from an otherwise innocuous appearing thunderstorm. However, the most severe hail and tornadoes are produced by thunderstorms. Both of these types of storms tend to form in environments high in wind shear, hurricanes and thunderstorms are considered to be the most destructive weather-related natural disasters. Although these weather phenomena are all related to clouds, they form and develop under different conditions. The relationship between these events and their formation requirements are used to develop models to predict the most frequent. This information is used to notify affected areas and save lives, severe thunderstorms can be assessed in three different categories.
These are approaching severe and significantly severe, approaching severe is defined as hail between 1⁄2 to 1 inch diameter or winds between 50 and 58 M. P. H. In the United States, such storms will usually warrant a Significant Weather Alert, severe is defined as hail 1 inch diameter or larger, winds 58 M. P. H. or stronger, or a tornado
An ice axe is a multi-purpose hiking and climbing tool used by mountaineers both in the ascent and descent of routes that involve frozen conditions with snow and/or ice. An ice axe can be held and employed in a number of different ways, in its simplest role, the ice axe is used like a walking stick in the uphill hand, the mountaineer holding the head in the center, with the pick pointing to the rear. It can be buried pick down, the rope tied around the shaft to form a secure anchor on which to bring up a second climber, or buried vertically to form a stomp belay. The adze is used to cut footsteps, as well as seats in the hillside. The long-handled alpenstock was a predecessor to the ice axe. The ice axe bears similarity in design to a war hammer. An ice axe is not only used as an aid to climbing, most ice axes meet design and manufacturing standards of organizations such as the Union Internationale des Associations dAlpinisme or European Committee for Standardization. There are two classifications of ice axe and Technical, Basic ice axes are designed for use in snow conditions for general mountaineering, and are adequate for basic support and self-arrest.
Technical ice axes, which may have curved shafts, are enough to be used for steep or vertical ice climbing and belaying. An ice axe consists of at least five components, Head – usually made of steel and featuring a pick, a hole in the center is provided for attaching a wrist leash or carabiner. Pick – the toothed pointed end of the head, typically slightly curved, adze – the flat, wide end of the head used for chopping steps in hard snow and ice. Hammer – the hammer is an alternative to the adze for those traveling in softer snow and it can be used as a more comfortable grip, or as a striking hammer. Shaft – straight or slightly angled, typically wider front-to-back than side-to-side, flat on the sides, traditional shafts were made of wood, but are now almost exclusively of lightweight metals or composites. Spike, or ferrule – a steel point at the base of the used for balance. Common ice axe accessories include, Leash – nylon webbing with a loop for securing the axe to hand. Often secured by a ring constrained to slide a limited distance on the shaft, Leash stop – a rubber keeper or metal stud preventing the leash from slipping off of the ice axe.
Snow basket – similar to baskets on ski poles, temporarily mounted on the close to the spike to keep the shaft from sinking into soft snow. Pick and adze guard – a cover to protect sharp edges
United States Coast Guard
The United States Coast Guard is a branch of the United States Armed Forces and one of the countrys seven uniformed services. This has happened twice, in 1917, during World War I, created by Congress on 4 August 1790 at the request of Alexander Hamilton as the Revenue Marine, it is the oldest continuous seagoing service of the United States. As Secretary of the Treasury, Hamilton headed the Revenue Marine, by the 1860s, the service was known as the U. S. Revenue Cutter Service and the term Revenue Marine gradually fell into disuse, the modern Coast Guard was formed by a merger of the Revenue Cutter Service and the U. S. Life-Saving Service on 28 January 1915, under the U. S. Department of the Treasury. As one of the five armed services, the Coast Guard has been involved in every U. S. war from 1790 to the Iraq War. As of 2014 the Coast Guard had over 36,000 men and women on duty,7,350 reservists,29,620 auxiliarists. In terms of size, the U. S. Coast Guard by itself is the worlds 12th largest naval force.
Because of its authority, the Coast Guard can conduct military operations under the U. S. Department of Defense or directly for the President in accordance with Title 14 USC 1–3. The Coast Guards enduring roles are maritime safety, security, to carry out those roles, it has 11 statutory missions as defined in 6 U. S. C. §468, which include enforcing U. S. law in the worlds largest exclusive economic zone of 3.4 million square miles, the Coast Guards motto is the Latin phrase, Semper Paratus. In a 2005 article in Time magazine following Hurricane Katrina, the author wrote, the Coast Guards most valuable contribution to may be as a model of flexibility, and most of all, spirit. Wil Milam, a swimmer from Alaska told the magazine, In the Navy. Practicing for war, training for war, in the Coast Guard, it was, take care of our people and the mission will take care of itself. The Coast Guard carries out three basic roles, which are subdivided into eleven statutory missions. Both agencies maintain rescue coordination centers to coordinate this effort, and have responsibility for military and civilian search and rescue.
The two services jointly provide instructor staff for the National Search and Rescue School that trains SAR mission planners and coordinators, previously located on Governors Island, New York, the school is now located at Coast Guard Training Center Yorktown at Yorktown, Virginia. The NRC takes Maritime Suspicious Activity and Security Breach Reports, details on the NRC organization and specific responsibilities can be found in the National Oil and Hazardous Substances Pollution Contingency Plan. The Marine Information for Safety and Law Enforcement database system is managed and used by the Coast Guard for tracking pollution, the five uniformed services that make up the U. S
Backpacking is the outdoor recreation of carrying gear on ones back, while hiking for more than a day. It is often but not always an extended journey, and may or may not involve camping outdoors, in North America tenting is common, where simple shelters and mountain huts found widely in Europe are rare. In New Zealand, tramping is an equivalent term though overnight huts are frequently used, hill walking is the equivalent in Britain, though backpackers make use of all kinds of accommodation, in addition to camping. Backpackers use simple huts in South Africa, similar terms used in other countries are trekking and bushwalking. Backpacking as a method of travel is a different activity, which mainly utilizes public transport during a journey which can last months, backpacking is an outdoor recreation where gear is carried in a backpack. This can include food, bedding, clothing, backpacking trips consist of at least one night and can last for weeks or months, sometimes aided by planned resupply points or drops.
A skilled backpacker minimizes their impact on the environment, including staying on established trails, not disturbing vegetation, the Leave No Trace movement ethos is direct, Leave nothing but footprints. Backpackers must always be prepared for difficulties, whether mishaps are experienced or not, the remoteness of backpacking locations can exacerbate any mishap. Survival gear and the skills to use it are paramount, backpacking camps are usually more spartan than campsites where gear is transported by car or boat. In areas with heavy traffic, a hike-in campsite might have a fire ring, an outhouse. Many hike-in camps are no more than level patches of free of underbrush. In remote wilderness areas hikers must choose their own site, established camps are rare and the ethos is to leave no trace when gone. In some regions, varying forms of accommodation exist, from simple log lean-tos to staffed facilities offering escalating degrees of service, beds and even drinks may be had at Alpine huts scattered among well-traveled European mountains.
In the more parts of Great Britain, especially Scotland. On the French system of long distance trails, Grande Randonnées, backpackers can stay in gîtes detapes, there are some simple shelters and occasional mountain hut provided in North America, including on the Appalachian trail. Another example is the High Sierra Camps in the Yosemite National Park, long distance backpacking trails with huts exist in South Africa, including the 100 km plus Amatola Trail, in the Eastern Cape Province. Backpacking is popular in the Himalayas, where porters and pack animals are often used, backpacking gear begins with a suitable backpack, proper both in size and fit. Next is clothing and footwear appropriate for expected conditions, third is an adequate amount and type of food
Baranof Island, sometimes called Baranov Island, Shee or Sitka Island, is an island in the northern Alexander Archipelago in the Alaska Panhandle, in Alaska. The name Baranof was given in 1805 by Imperial Russian Navy captain U. F. Lisianski to honor Alexander Andreyevich Baranov and it was called Sheet’-ká Xáatl by the native Tlingit people. It is the smallest of the ABC islands of Alaska, the island has a land area of 1,607 square miles, which is slightly smaller than the State of Delaware. It measures 105 miles by 30 miles at its longest point and perpendicular widest point and it has a shoreline of 617 miles. Its center is near 57°0′N 135°0′W, most of the island lies within the limits of Tongass National Forest. A large part has been designated as the South Baranof Wilderness. A little bay called Ommaney Bay is located in the end of the island. The escort carrier USS Ommaney Bay bears its name, the population of the island was 8,532 at the 2000 census. Almost the entire area of the island is part of the City, the only part of Baranof that is not in Sitka is a tiny sliver of land at the extreme southeast corner, which is in the Petersburg Census Area, and includes the town of Port Alexander.
This section had a 2000 census population of 81 persons, the towns of Baranof Warm Springs, Port Armstrong, and Port Walter are located on the eastern side of the island. Goddard, a settlement about 16 miles south of Sitka, features a few private homes. The latter is accessible by road from Sitka. All of these communities, except for Port Alexander and Port Armstrong, are under the jurisdiction of the City and Borough of Sitka, of which, Sitka serves as the borough seat. Fishing, seafood processing, and tourism are important industries on the island, the island was the center of Russian activity in North America during the period from 1804 to 1867 and was the headquarters of the Russian fur-trading interest. Around 1900, Baranof Island was subject to many mining ventures, especially centered on Sitka. Canneries, whaling stations, and fox farms were established on Baranof Island and smaller islands around it, the remains of these outposts are still evident, though most exist in a dilapidated condition.
In February 1924 the Alaska Territorial Game Commission hired Charlie Raatakainen to transplant mainland goats from near Juneau to Bear Mountain, Raatakainen hired a group of Finns aboard his boat the Pelican to complete the job, though one of the group died in the process. The 1939 Slattery Report on Alaskan development identified the island as one of the areas where new settlements would be established through immigration, louis LAmours novel Sitka describes conflict between the Russian fur trading empire and Yankee settlers
A crevasse is a deep crack, or fracture, found in an ice sheet or glacier, as opposed to a crevice that forms in rock. Crevasses form as a result of the movement and resulting stress associated with the shear stress generated when two pieces above a plastic substrate have different rates of movement. The resulting intensity of the stress causes a breakage along the faces. Crevasses often have vertical or near-vertical walls, which can melt and create seracs, arches. These walls sometimes expose layers that represent the glaciers stratigraphy, Crevasse size often depends upon the amount of liquid water present in the glacier. A crevasse may be as deep as 45 metres, as wide as 20 metres, a crevasse may be covered, but not necessarily filled, by a snow bridge made of the previous years accumulation and snow drifts. The result is that crevasses are rendered invisible, and thus potentially lethal to anyone attempting to navigate their way across a glacier, occasionally a snow bridge over an old crevasse may begin to sag, providing some landscape relief, but this cannot be relied upon.
Anyone planning to travel on a glacier should be trained in crevasse rescue, the presence of water in a crevasse can significantly increase its penetration. Longitudinal crevasses form parallel to flow where the width is expanding. They develop in areas of stress, such as where a valley widens or bends. They are typically concave down and form a greater than 45° with the margin. Splashing crevasses result from shear stress from the margin of the glacier and they extend from the glaciers margin and are concave up with respect to glacier flow, making an angle less than 45° with the margin. At the centre line of the glacier, there is zero pure shear from the margins, transverse crevasses are the most common crevasse type. They form in a zone of longitudinal extension where the stresses are parallel to the direction of glacier flow. These crevasses stretch across the glacier transverse to the flow direction and they generally form where a valley becomes steeper. Bergschrund Bowie Crevasse Field Glaciology Paterson, W. S.
B,1994, The Physics of Glaciers, 3rd edition, ISBN 0-7506-4742-6. Boon, S. M. J. Sharp,2003, The role of hydrologically-driven ice fracture in drainage system evolution on an Arctic glacier, Geophysical Research Letters,30, pp.1916. Van der Veen, C. J.1998, Fracture mechanics approach to penetration of surface crevasses on glaciers, Cold Regions Science and Technology,27, pp. 31–47
United States Geological Survey
The United States Geological Survey is a scientific agency of the United States government. The scientists of the USGS study the landscape of the United States, its resources. The organization has four science disciplines, concerning biology, geology. The USGS is a research organization with no regulatory responsibility. The USGS is a bureau of the United States Department of the Interior, the USGS employs approximately 8,670 people and is headquartered in Reston, Virginia. The USGS has major offices near Lakewood, Colorado, at the Denver Federal Center, the current motto of the USGS, in use since August 1997, is science for a changing world. The agencys previous slogan, adopted on the occasion of its anniversary, was Earth Science in the Public Service. Prompted by a report from the National Academy of Sciences, the USGS was created, by a last-minute amendment and it was charged with the classification of the public lands, and examination of the geological structure, mineral resources, and products of the national domain.
This task was driven by the need to inventory the vast lands added to the United States by the Louisiana Purchase in 1803, the legislation provided that the Hayden and Wheeler surveys be discontinued as of June 30,1879. Clarence King, the first director of USGS, assembled the new organization from disparate regional survey agencies, after a short tenure, King was succeeded in the directors chair by John Wesley Powell. Administratively, it is divided into a Headquarters unit and six Regional Units, Other specific programs include, Earthquake Hazards Program monitors earthquake activity worldwide. The National Earthquake Information Center in Golden, Colorado on the campus of the Colorado School of Mines detects the location, the USGS runs or supports several regional monitoring networks in the United States under the umbrella of the Advanced National Seismic System. The USGS informs authorities, emergency responders, the media, and it maintains long-term archives of earthquake data for scientific and engineering research.
It conducts and supports research on long-term seismic hazards, USGS has released the UCERF California earthquake forecast. The USGS National Geomagnetism Program monitors the magnetic field at magnetic observatories and distributes magnetometer data in real time, the USGS operates the streamgaging network for the United States, with over 7400 streamgages. Real-time streamflow data are available online, since 1962, the Astrogeology Research Program has been involved in global and planetary exploration and mapping. USGS operates a number of related programs, notably the National Streamflow Information Program. USGS Water data is available from their National Water Information System database
Hazards of outdoor recreation
Outdoor recreation, such as hiking, canoeing, cycling, or skiing, entails risks, even if participants do not recklessly place themselves in harms way. In some circumstances, such as being in remote locations or in extreme weather conditions, with correct precautions, even fairly adventurous outdoor recreation can be enjoyable and safe. Every hazard has its own safety measure, and every ailment a particular remedy, a standard precaution for all back country activities is carrying the ten essentials, a collection of tools chosen for their utility in preventing or reacting to various emergencies. The common practice of traveling in a group improves safety in all regards, if one person is injured, group members can administer first aid or seek help. A group can avoid poor decisions that a lone traveler might make, if an emergency occurs, a group can pool its muscle power, brain power, and body heat. Another precaution is informing people outside of the group of the itinerary, a communication device, such as a cell phone or a satellite phone, may help in the case of an emergency.
However, with the exception of mountain tops that are in line-of-sight to populated areas, in the wilderness one should always be prepared to hike out for help, if necessary. Blizzards, flash floods, dust or sandstorms and other events may or may not be predictable. Lightning is a frequent and serious threat in many regions, backcountry avalanches are generally triggered by the immediate action of the party. Other non-avalanche snow immersions can be dangerous, including tree wells. Other mass movements include icefalls and rockfalls, when choosing a campsite care must be taken to avoid those along with dead trees, trees with large dead branches, or trees that have previously been through a forest fire. Collectively, these are called widowmakers by experienced campers, slips may occur, On wet rocks or logs. When crossing streams, rivers and other bodies of water, which can be due to poor visibility, uneven surfaces and algae or moss-covered rocks. The tops of waterfalls are dangerous because of fast moving water and smooth.
Rubber soles grip poorly on slime, compared to felt soles, loose gravel or scree on top of smooth rock acts like ball bearings. Precautions include spotting the situation ahead, keeping knees bent and weight forward, using hiking sticks, ice When travelling over glaciers, crevasses pose a grave danger. These giant cracks in the ice are not always visible, as snow can be blown, at times snowbridges can be as thin as a few inches. Climbers and hikers use ropes to protect themselves from such hazards, basic gear for glacier travel includes crampons and ice axes, and teams of two to five tie into a rope equally spaced
Baranof Lake is a glacially-fed, horseshoe-shaped lake on the eastern side of Baranof Island, in Alaska. Baranof Lake borders the community of Baranof Warm Springs and has a Forest Service cabin on the end of the lake. Baranof River flows into the western end and exits on the eastern end in rapids. Baranof Lake was likely named for the community of Baranof Warm Springs, U. S. Geological Survey Geographic Names Information System, Baranof Lake
A crampon is a traction device that is attached to footwear to improve mobility on snow and ice during ice climbing. There are three main attachment systems for footwear, step-in, and strap bindings, the first two require boots with welts, as a tension lever attaches the crampon to the heel. The last type are more versatile and can adapt to any boot or shoe. Oscar Eckenstein designed the first 10-point crampon in 1908, dramatically reducing the need for step cutting and this design was made commercially available by the Italian Henry Grivel. Crampons are made of alloy, light weight aluminium, or a combination of the two. Lighter weight crampons are popular for ski touring where demands are generally lower. Early 10-point crampons lacked forward angled spikes and thus required step cutting on steep terrain, in the 1930s two additional forward-slanting points were added, making them exceptional for mountaineering and glacier travel and beginning a revolution in front pointing. There is currently a range of models, including specialized crampons with as many as 14 points, crampons are fastened to footwear by means of a binding system.
Crampons use a full system and a hybrid binding that features a toe strap at the front. To prevent snow from balling up under crampons, especially in temperatures around freezing, rubber models use flexion to repel snow while plastic anti-balling plates employ a hydrophobic surface to prevent adhesion. Crampons are graded C1, C2 and C3 relative to their flexibility, No crampons are suitable for B0 boots. Specialized ski crampons are employed in ski mountaineering on hard snow, cleats Scandinavian crampon Crampon Review from Climbing Magazine, No. Caltech Alpine Clubs guide to crampons at the Wayback Machine