HMS Europa (1783)
HMS Europa was a 50-gun fourth-rate of the Royal Navy, built by Woolwich Dockyard in 1783. Europa was based out of Jamaica, ran aground at Montego Bay in 1785, but was not damaged; when reports of the outbreak of the French Revolutionary Wars reached the British posts in Jamaica, Europa was sent into action along with the entire British squadron based at Jamaica, which consisted of several 12-pounder frigates and a number of smaller vessels, under the command of Commodore John Ford. In April 1793, when the Royal Navy station in Jamaica received word of the War of the First Coalition, the naval squadron based at Jamaica, under the command of Commodore John Ford, became active. Europa served as a troop transport, helped capture French merchant vessels, carrying produce and supplies. On 1 June 1794, Europa assisted HMS Belliqueux, HMS Penelope, HMS Sceptre in attacking French fortifications during the capture of Port-au-Prince, Haiti. Europa, under the command of James Stephenson, served as a troopship during the British expedition to Egypt in 1801.
There she participated in the landing at Aboukir Bay, an overwhelming attack that defeated the French and led to the British capture of Cairo. Because Europa served in the navy's Egyptian campaign between 8 March 1801 and 2 September, her officers and crew qualified for the clasp "Egypt" to the Naval General Service Medal, which the Admiralty issued in 1847 to all surviving claimants; the Principal Officers and Commissioners of His Majesty's Navy offered the "Europa, of 50 guns and 1047 tons", lying at Portsmouth, for sale on 11 August 1814. The buyer had to post a bond of £3,000, with two guarantors, that they would break up the vessel within a year of purchase. Europa was sold in 1814. Joseph Whidbey - Royal Navy officer, served on the Vancouver Expedition, namesake of Whidbey Island, Joseph Whidbey State Park in Washington State and Whidbey Reach, Gardner Canal, British Columbia. George Vancouver - Royal Navy officer, commanded the 1791-95 expedition along North America's Pacific Coast. Namesake of Vancouver Island, British Columbia, Washington, Mount Vancouver, Mount Vancouver.
James Vashon - Royal Navy officer, served on the Vancouver Expedition, namesake of Vashon Island, Washington. Henry Digby - Senior Royal Navy officer, nephew of Admiral Robert Digby, notably saved the crew of HMS Boyne when it was accidentally set on fire at Spithead, Great Britain. Peter Puget - Royal Navy officer, namesake of the Puget Sound, which he explored. Named after him is Puget Island, Washington State. Joseph Baker - Royal Navy officer, served on the Vancouver Expedition as a mapmaker and surveyor. Namesake of Mt. Baker. John Bligh - Royal Navy officer, served during the American War of Independence and the Napoleonic Wars. John Cooke - Royal Navy officer, served during the American War of Independence, the French Revolutionary Wars, the Napoleonic Wars. Killed at the Battle of Trafalgar in 1805, in hand-to-hand combat. Britainsnavy.co.uk Phenyon.plus.com
Magazine (artillery)
Magazine is the name for an item or place within which ammunition or other explosive material is stored. It is taken from the Arabic word "makhāzin", meaning storehouses, via Italian and Middle French; the term is used for a place where large quantities of ammunition are stored for distribution, or an ammunition dump. This usage is less common. In the early history of tube artillery drawn by horses, ammunition was carried in separate unarmored wagons or vehicles; these soft-skinned vehicles were vulnerable to enemy fire and to explosions caused by a weapons malfunction. Therefore, as part of setting up an artillery battery, a designated place would be used to shelter the ready ammunition. In the case of batteries of towed artillery the temporary magazine would be placed, if possible, in a pit, or natural declivity, or surrounded by sandbags or earthworks. Circumstances might require the establishment of multiple field magazines so that one lucky hit or accident would not disable the entire battery.
The ammunition storage area aboard a warship is referred to as a magazine or the "ship's magazine" by sailors. When artillery was fired with gunpowder, a warship's magazines were built below the water line—especially since the magazines could be flooded in case of fire or other dangerous emergencies on board the ship. An open flame was never allowed inside the magazine. More modern warships use automated ammunition hoists; the path through which the naval artillery's ammunition passed has blast-resistant airlocks and other safety devices, including provisions to flood the compartment with seawater in an emergency. The separation of shell and propellant gave the storage of the former the name "shell room" and the latter "powder room". Surface warships that have carried torpedoes, ones that still do, have had torpedo magazines for carrying these dangerous antiship and antisubmarine weapons in well-defended compartments. With the advent of missile-equipped warships, the term missile "magazine" has been applied to the storage area for guided missiles on the ship carried below the main decks of the warships.
For ships with both forward and aft surface-to-air missile launchers, there are at least two missile magazines. Sometimes the magazines of guided-missile frigates and guided-missile destroyers have carried or do carry a mixture of various types of missiles: surface-to-air missiles, antisubmarine missiles such as the ASROC missile, antiship missiles such as the Harpoon missile. See the Oliver Hazard Perry-class frigates, owned by several different navies around the world, in which one 40-missile magazine carries a mixture of all three types of missiles: surface-to-air, surface-to-surface, surface-to-underwater. In aircraft carriers, the magazines are required to store not only the aircraft carrier's own defensive weapons, but all of the weapons for her warplanes, including rapid-fire gun ammunition, air-to-air missiles such as the Sidewinder missile, air-to-surface missiles such as the Maverick missile, Mk 46 ASW torpedoes, Joint Direct Attack Munitions, "dumb bombs", HARM missiles, antiship missiles such as the Harpoon missile and the Exocet missile.
Nearly every detail of nuclear weapons storage is classified, although many of the same principles of an ammunition dump would apply. The one consistent factor is the increased security compared to that afforded to the storage of other weapons. In naval usage, most nuclear weapons are stored fitted to launch vehicles in the launch position, their vertical launching system tubes and missile tubes could technically be described as magazines. Nuclear weapon magazines exist for other nuclear weapons such as nuclear gravity bombs and air-launched cruise missiles aboard aircraft carriers, on other surface ships armed with nuclear depth charges though it is believed that since the end of the Cold War that most nations have progressively retired these weapons or chosen to store these weapons on land; the United States employs the Weapons Storage and Security System for storing its tactical nuclear weapons in Europe. Ammunition dump Armory Arsenal Gunpowder magazine Colonial Williamsburg Magazine
HMS Discovery (1789)
HMS Discovery was a Royal Navy ship launched in 1789 and best known as the lead ship in George Vancouver's exploration of the west coast of North America in his famous 1791-1795 expedition. She was participated in the Battle of Copenhagen. Thereafter she served as a hospital ship and as a convict ship until 1831, she was broken up in 1834. Discovery was launched in 1789 and purchased for the Navy in 1790, she was named after the previous HMS Discovery, one of the ships on James Cook's third voyage to the Pacific Ocean. The earlier Discovery was the ship. Discovery was a full-rigged ship with a standard crew complement of 100 including a widow's man, she had been built for a voyage of exploration to the Southern whale fisheries. Discovery's first captain was Henry Roberts, with Vancouver as his first lieutenant, but when the Nootka Crisis began in 1789, Roberts and Vancouver were posted elsewhere. The ship became a depot for processing sailors brought in by press gangs in Chatham. Vancouver returned and was given full command of Discovery to assist with the Nootka Sound Conventions.
On 1 April 1791, Discovery left England with HMS Chatham. Both ships stopped at Cape Town before exploring the south coast of Australia. In King George Sound, the Discovery's naturalist and surgeon Archibald Menzies collected various plant species including Banksia grandis; this was the first recording of the genus Banksia from Western Australia. The two ships sailed to Hawaii where Vancouver met Kamehameha I. Chatham and Discovery sailed on to the Northwest Pacific. Over the course of the next four years, Vancouver surveyed the northern Pacific Ocean coast in Discovery wintering in Spanish California or Hawaii. Vancouver named many features after friends and associates, including: Mount Baker, named after 3rd Lieutenant Joseph Baker, the first on the expedition to spot it Mount St. Helens, named after Alleyne Fitzherbert, 1st Baron St Helens Puget Sound, after Discovery's lieutenant Peter Puget, who explored its southern reaches. Mount Hood Mount Rainier Discovery Bay and Port Discovery. Discovery's primary mission was to exert British sovereignty over this part of the Northwest Coast following the hand-over of the Spanish Fort San Miguel at Nootka Sound, although exploration in co-operation with the Spanish was seen as an important secondary objective.
Exploration work was successful. Vancouver and the Spanish commandant Juan Francisco de la Bodega y Quadra were on such good terms that the original name of Vancouver Island was Vancouver and Quadra's Island. In 1793, Discovery entered a bay on the northern end of the Prince of Wales Island when a storm arose, its shelter led to it being named Port Protection. Baker Point, the northwest point of Prince of Wales Island is named after the Discovery's 3rd Lieutenant Joseph Baker, it is remarkable that during Discovery's five-year voyage she lost only six sailors, all in accidents. Discovery was meant to bring a resolution to the disposition of control over Nootka Sound, but despite four years of dispatches with their home governments and Quadra failed to formally conclude an agreement. Discovery put into St Helena in July 1795. There on 2 July 1795 Discovery and the brig Chatham captured a Dutch East Indiaman, the Makassar, which sailed in, unaware that the newly established Batavian Republic was at war with Great Britain.
Some prize money was due to be paid in November 1824. From there Vancouver and Discovery sailed in convoy with Sceptre, the East Indiaman General Goddard, their prizes, a large number of other East Indiamen, they arrived at Shannon in September and Discovery sailed on to England. After four years at sea, Discovery was in great need of a refit, she was laid up until 1798 when she was refitted as a bomb vessel and recommissioned under Commander John Dick. In October 1800 Commander John Conn replaced Dick. Discovery participated in the Battle of Copenhagen in April 1801. In 1847 the Admiralty authorized the issuance of the Naval General Service medal with clasp "Copenhagen 1801" to all surviving claimants from the campaign. On 4 August 1801, Discovery served with Nelson when he resolved to attack an enemy flotilla off Boulogne using Bomb vessels. On the night of 15 August, the British attacked in four divisions, with Conn in charge of four boats armed with howitzers. Discovery had one man wounded in the unsuccessful British attack.
Discovery was paid off in October and laid up in ordinary in May 1802. Discovery was recommissioned in May 1803 under Commander John Joyce, with Commander Charles Pickford replacing him in August. Pickford continued in command until 1805. In 1807 Discovery was at Sheerness, she continued in this role until 1815. In 1818 Discovery was converted to a convict ship at Woolwich. In 1824 she moved to Deptford, where she continued to serve as a convict ship until at least 1831, she was broken up there in 1834. Among the notable persons who served on Discovery's great voyage: Captain George Vancouver 1st Lieutenant Zachary Mudge - promoted to admiral in 1849 2nd Lieutenant Peter Puget - promoted to rear admiral in 1821 3rd Lieutenant Joseph Baker - Post captain in 1809 Master Joseph Whidbey - a naval engineer noted for the breakwater at Plymouth Thomas Manby - master's mate, promoted to lieutenant on Discovery William Robert Broughton - in command of Chatham a rear-admiral Archibald Menzies - naturalist and surgeon Thomas Pitt, 2nd Baron Camelford - sent back to England in disgrace.
Robert Barrie - commissioner of the dockyard at Kingston, Upper Canada European and American voyages of scientific explor
Archibald Menzies
Archibald Menzies was a Scottish surgeon and naturalist. He spent many years at sea, serving with the Royal Navy, private merchants, the Vancouver Expedition, he was the first recorded European to reach the summit of the Hawaiian volcano Mauna Loa and introduced the Monkey Puzzle tree to England. Menzies was born in Perthshire, Scotland. While working with his elder brother William at the Royal Botanic Gardens, he drew the attention of Dr John Hope, professor of botany at Edinburgh University, who encouraged him to study medicine there. Having qualified as a surgeon, Menzies served as assistant to a doctor in Caernarvon, Wales joined the Royal Navy as assistant surgeon on HMS Nonsuch. Present at Battle of the Saintes, in peacetime Menzies served on Halifax Station in Nova Scotia. In 1786 Menzies was appointed surgeon on board the Prince of Wales, on a fur-trading voyage round Cape Horn to the northern Pacific; this ship, in company of Princess Royal, visited North America and Hawaii several times.
Menzies returned to Great Britain in 1789. He was elected a fellow of the Linnean Society in 1790. In 1790, Menzies was appointed as naturalist to accompany Captain George Vancouver on his voyage around the world on HMS Discovery; when the surgeon fell ill, Menzies took over his duties. In 1794, while Discovery spent one of three winters in Hawaii, with Lieutenant Joseph Baker and two other men, made the first recorded ascent to Mokuaweoweo, the summit of Mauna Loa. Menzies used a portable barometer to measure the height of the mountain as 13,564 feet compared to its known height of 13,679 feet, it would be forty years before another European, fellow Scotsman David Douglas, would reach the summit on 29 January 1834. In 1795, Menzies was served the seeds of the Chile Pine, Araucaria araucana, as a dessert while dining with the Viceroy of Chile, he was able to pop some seeds into his pocket and grow them on board ship on the way back to Europe, returned to England with five healthy plants, the first seen in Britain.
Known as the Monkey Puzzle tree, the Chile Pine became a favourite in most formal gardens of the nineteenth century. After the voyage, Menzies served with the Navy in the West Indies, he received the degree of M. D. at the University of Aberdeen in 1799. After retiring from the Navy he became a surgeon at Notting Hill, London, he became the father of the Linnean Society upon the death of Aylmer Bourke Lambert. Menzies's wife died in 1837, they had no children. Menzies himself is buried in Kensal Green cemetery. Menzies' name is commemorated in the scientific names of several of the plants he discovered, including Menziesia, a genus of shrubs in the Ericaceae, the Douglas fir Pseudotsuga menziesii, the most commercially important tree in western North America; the Pacific madrone, an evergreen tree and largest of the Ericaceae, was named Arbutus menziesii in his honour by Friedrich Pursh. Named for Menzies, in a corrupted form as adapted by the Nuxalk people of the Bella Coola area of the Central Coast of British Columbia, is "Bensins Island", as recorded by Alexander Mackenzie during his visit there shortly after Vancouver's ship visited the area.
The Ainapo Trail he used to climb Mauna Loa is known as "Menzies Trail". One of the principal streets surrounding the Legislative Assembly of British Columbia in Victoria, British Columbia is named Menzies street. Many of the specimens collected by Menzies are planted in London's Kew Gardens, he brought back to London 112 separate collections of artefacts, which are housed at the British Museum. A comprehensive catalogue of these collections was not published until 1951. European and American voyages of scientific exploration Newcombe, C. F.. "Menzies' journal of Vancouver's voyage". Memoir V. Archives British Columbia. CS1 maint: Extra text: authors list Eastwood, Alice. "Archibald Menzies' journal of the Vancouver Expedition Extracts covering the visit to California". Quarterly of the California Historical Society. 2. CS1 maint: Extra text: authors list Jepson, W. L.. "The botanical explorers of California: Archibald Menzie ". Madroño. 1. Galloway, D. J. and E. W. Groves. "Archibald Menzies, MD, F. L. S.: Aspects of his life and collections".
Archives of Natural History. 14. Captain Vancouver, Northwest Navigator, E. C. Coleman. Tempus Publishing 2006. Archibald Menzies on www.victorialodging.com
River Thames
The River Thames, known alternatively in parts as the Isis, is a river that flows through southern England including London. At 215 miles, it is the longest river in England and the second longest in the United Kingdom, after the River Severn, it flows through Oxford, Henley-on-Thames and Windsor. The lower reaches of the river are called the Tideway, derived from its long tidal reach up to Teddington Lock, it rises at Thames Head in Gloucestershire, flows into the North Sea via the Thames Estuary. The Thames drains the whole of Greater London, its tidal section, reaching up to Teddington Lock, includes most of its London stretch and has a rise and fall of 23 feet. Running through some of the driest parts of mainland Britain and abstracted for drinking water, the Thames' discharge is low considering its length and breadth: the Severn has a discharge twice as large on average despite having a smaller drainage basin. In Scotland, the Tay achieves more than double the Thames' average discharge from a drainage basin, 60% smaller.
Along its course are 45 navigation locks with accompanying weirs. Its catchment area covers a small part of western England; the river contains over 80 islands. With its waters varying from freshwater to seawater, the Thames supports a variety of wildlife and has a number of adjoining Sites of Special Scientific Interest, with the largest being in the remaining parts of the North Kent Marshes and covering 5,449 hectares; the Thames, from Middle English Temese, is derived from the Brittonic Celtic name for the river, recorded in Latin as Tamesis and yielding modern Welsh Tafwys "Thames". The name may have meant "dark" and can be compared to other cognates such as Russian темно, Lithuanian tamsi "dark", Latvian tumsa "darkness", Sanskrit tamas and Welsh tywyll "darkness" and Middle Irish teimen "dark grey"; the same origin is shared by countless other river names, spread across Britain, such as the River Tamar at the border of Devon and Cornwall, several rivers named Tame in the Midlands and North Yorkshire, the Tavy on Dartmoor, the Team of the North East, the Teifi and Teme of Wales, the Teviot in the Scottish Borders, as well as one of the Thames' tributaries called the Thame.
Kenneth H. Jackson has proposed that the name of the Thames is not Indo-European, while Peter Kitson suggested that it is Indo-European but originated before the Celts and has a name indicating "muddiness" from a root *tā-,'melt'. Indirect evidence for the antiquity of the name'Thames' is provided by a Roman potsherd found at Oxford, bearing the inscription Tamesubugus fecit, it is believed. Tamese was referred to as a place, not a river in the Ravenna Cosmography; the river's name has always been pronounced with a simple t /t/. A similar spelling from 1210, "Tamisiam", is found in the Magna Carta; the Thames through Oxford is sometimes called the Isis. And in Victorian times and cartographers insisted that the entire river was named the Isis from its source down to Dorchester on Thames and that only from this point, where the river meets the Thame and becomes the "Thame-isis" should it be so called. Ordnance Survey maps still label the Thames as "River Isis" down to Dorchester. However, since the early 20th century this distinction has been lost in common usage outside of Oxford, some historians suggest the name Isis is nothing more than a truncation of Tamesis, the Latin name for the Thames.
Sculptures titled Tamesis and Isis by Anne Seymour Damer can be found on the bridge at Henley-on-Thames, Oxfordshire. Richard Coates suggests that while the river was as a whole called the Thames, part of it, where it was too wide to ford, was called *lowonida; this gave the name to a settlement on its banks, which became known as Londinium, from the Indo-European roots *pleu- "flow" and *-nedi "river" meaning something like the flowing river or the wide flowing unfordable river. For merchant seamen, the Thames has long been just the "London River". Londoners refer to it as "the river" in expressions such as "south of the river"; the river gives its name to three informal areas: the Thames Valley, a region of England around the river between Oxford and West London. Thames Valley Police is a formal body. In non-administrative use, the river's name is used in those of Thames Valley University, Thames Water, Thames Television, publishing company Thames & Hudson and South Thames College. An example of its use in the names of historic entities is the Thames Ironworks and Shipbuilding Company.
The administrative powers of the Thames Conservancy have been taken on with modifications by the Environment Agency and, in respect of the Tideway part of the river, such powers are split between the agency and the Port of London Authority. The marks of human activity, in some cases dating back to Pre-Roman Britain, are visible at various points along the river; these include a variety of structure
George Vancouver
Captain George Vancouver was a British officer of the Royal Navy best known for his 1791–95 expedition, which explored and charted North America's northwestern Pacific Coast regions, including the coasts of what are now the American states of Alaska and Oregon, as well as the province of British Columbia in Canada. He explored the Hawaiian Islands and the southwest coast of Australia. Vancouver Island and the city of Vancouver, British Columbia are named for him, as is Vancouver, Washington. Mount Vancouver of Yukon and Alaska, on the Canadian-American border and New Zealand's sixth highest mountain, are named for him. George Vancouver was born in the seaport town of King's Lynn on 22 June 1757 as the sixth, youngest, child of John Jasper Vancouver, a Dutch-born Deputy Collector of Customs, Bridget Berners. In 1771, at the age of 13, Vancouver entered the Royal Navy as a "young gentleman," a future candidate for midshipman, he was selected to serve as a midshipman aboard HMS Resolution, on James Cook's second voyage searching for Terra Australis.
He accompanied Cook's third voyage, this time aboard Resolution's companion ship, HMS Discovery, was present during the first European sighting and exploration of the Hawaiian Islands. Upon his return to Britain in October 1780, Vancouver was commissioned as a lieutenant and posted aboard the sloop HMS Martin on escort and patrol duty in the English Channel and North Sea, he accompanied the ship. On 7 May 1782 he was appointed fourth Lieutenant of the 74-gun ship of the line HMS Fame, at the time part of the British West Indies Fleet and assigned to patrolling the French-held Leeward Islands. Vancouver returned to England in June 1783. In the late 1780s the Spanish Empire commissioned an expedition to the Pacific Northwest; the 1789 the Nootka Crisis developed, Spain and Britain came close to war over ownership of the Nootka Sound on contemporary Vancouver Island, of greater importance, the right to colonise and settle the Pacific Northwest coast. Henry Roberts had taken command of the survey ship HMS Discovery, to be used on another round-the-world voyage, Roberts selected Vancouver as his first lieutenant, but they were diverted to other warships due to the crisis.
Vancouver went with Joseph Whidbey to the 74-gun ship of the line HMS Courageux. When the first Nootka Convention ended the crisis in 1790, Vancouver was given command of Discovery to take possession of Nootka Sound and to survey the coasts. Departing England with two ships, HMS Discovery and HMS Chatham, on 1 April 1791, Vancouver commanded an expedition charged with exploring the Pacific region. In its first year the expedition travelled to Cape Town, New Zealand and Hawaii, collecting botanical samples and surveying coastlines along the way, he formally claimed at Possession Point, King George Sound Western Australia, now the town of Albany, Western Australia for the British. Proceeding to North America, Vancouver followed the coasts of present-day Oregon and Washington northward. In April 1792 he encountered American Captain Robert Gray off the coast of Oregon just prior to Gray's sailing up the Columbia River. Vancouver entered the Strait of Juan de Fuca, between Vancouver Island and the Washington state mainland on 29 April 1792.
His orders included a survey of every inlet and outlet on the west coast of the mainland, all the way north to Alaska. Most of this work was in small craft propelled by both oar. Vancouver named many features for his officers, friends and his ship Discovery, including: Mount Baker – after Discovery's 3rd Lieutenant Joseph Baker, the first on the expedition to spot it Mount St. Helens – after his friend, Alleyne Fitzherbert, 1st Baron St Helens Puget Sound – after Discovery's 2nd lieutenant Peter Puget, who explored its southern reaches. Mount Rainier – after his friend, Rear Admiral Peter Rainier. Port Gardner and Port Susan, Washington – after his former commander Vice Admiral Sir Alan Gardner and his wife Susannah, Lady Gardner. Whidbey Island – after naval engineer Joseph Whidbey. Discovery Passage, Discovery Island, Discovery Bay and Port Discovery. Vancouver was the second European to enter Burrard Inlet on 13 June 1792, naming it for his friend Sir Harry Burrard, it is the present day main harbour area of the City of Vancouver beyond Stanley Park.
He surveyed Jervis Inlet over the next nine days. On his 35th birthday on 22 June 1792, he returned to Point Grey, the present-day location of the University of British Columbia. Here he unexpectedly met a Spanish expedition led by Dionisio Alcalá Galiano and Cayetano Valdés y Flores. Vancouver was "mortified" to learn they had a crude chart of the Strait of Georgia based on the 1791 exploratory voyage of José María Narváez the year before, under command of Francisco de Eliza. For three weeks they cooperatively explored the Georgia Strait and the Discovery Islands area before sailing separately towards Nootka Sound. After the summer surveying season ended, in August 1792, Vancouver went to Nootka the region's most important harbour, on contemporary Vancouver Island. Here he was to receive any British buildings and lands returned by the Spanish from claims by Francisco de Eliza for the Spanish crown; the Spanish commander, Juan Francisco Bodega y Quadra, was cordial and he and Vancouver exchanged the maps they had made, but no agreement was reached.
At this time, they decided to name t
Mauna Loa
Mauna Loa is one of five volcanoes that form the Island of Hawaii in the U. S. state of Hawaiʻi in the Pacific Ocean. The largest subaerial volcano in both mass and volume, Mauna Loa has been considered the largest volcano on Earth, dwarfed only by Tamu Massif, it is an active shield volcano with gentle slopes, with a volume estimated at 18,000 cubic miles, although its peak is about 125 feet lower than that of its neighbor, Mauna Kea. Lava eruptions from Mauna Loa are silica-poor and fluid, they tend to be non-explosive. Mauna Loa has been erupting for at least 700,000 years, may have emerged above sea level about 400,000 years ago; the oldest-known dated rocks are not older than 200,000 years. The volcano's magma comes from the Hawaii hotspot, responsible for the creation of the Hawaiian island chain over tens of millions of years; the slow drift of the Pacific Plate will carry Mauna Loa away from the hotspot within 500,000 to one million years from now, at which point it will become extinct.
Mauna Loa's most recent eruption occurred from March 24 to April 15, 1984. No recent eruptions of the volcano have caused fatalities, but eruptions in 1926 and 1950 destroyed villages, the city of Hilo is built on lava flows from the late 19th century; because of the potential hazards it poses to population centers, Mauna Loa is part of the Decade Volcanoes program, which encourages studies of the world's most dangerous volcanoes. Mauna Loa has been monitored intensively by the Hawaiian Volcano Observatory since 1912. Observations of the atmosphere are undertaken at the Mauna Loa Observatory, of the Sun at the Mauna Loa Solar Observatory, both located near the mountain's summit. Hawaii Volcanoes National Park covers the summit and the southeastern flank of the volcano, incorporates Kīlauea, a separate volcano. Like all Hawaiian volcanoes, Mauna Loa was created as the Pacific tectonic plate moved over the Hawaii hotspot in the Earth's underlying mantle; the Hawaii island volcanoes are the most recent evidence of this process that, over 70 million years, has created the 3,700 mi -long Hawaiian–Emperor seamount chain.
The prevailing view states that the hotspot has been stationary within the planet's mantle for much, if not all of the Cenozoic Era. However, while the Hawaiian mantle plume is well understood and extensively studied, the nature of hotspots themselves remains enigmatic. Mauna Loa is one of five subaerial volcanoes; the oldest volcano on the island, Kohala, is more than a million years old, Kīlauea, the youngest, is believed to be between 300,000 and 600,000 years of age. Lōʻihi Seamount on the island's flank is younger, but has yet to breach the surface of the Pacific Ocean. At 1 million to 700,000 years of age, Mauna Loa is the second youngest of the five volcanoes on the island, making it the third youngest volcano in the Hawaiian – Emperor seamount chain, a chain of shield volcanoes and seamounts extending from Hawaii to the Kuril–Kamchatka Trench in Russia. Following the pattern of Hawaiian volcano formation, Mauna Loa would have started as a submarine volcano building itself up through underwater eruptions of alkali basalt before emerging from the sea through a series of surtseyan eruptions about 400,000 years ago.
Since the volcano has remained active, with a history of effusive and explosive eruptions, including 33 eruptions since the first well-documented eruption in 1843. Although Mauna Loa's activity has been overshadowed in recent years by that of its neighbor Kīlauea, it remains active. Mauna Loa is the largest subaerial and second largest overall volcano in the world, covering a land area of 5,271 km2 and spans a maximum width of 120 km. Consisting of 65,000 to 80,000 km3 of solid rock, it makes up more than half of the surface area of the island of Hawaiʻi. Combining the volcano's extensive submarine flanks and 4,170 m subaerial height, Mauna Loa rises 9,170 m from base to summit, greater than the 8,848 m or 29,029 ft elevation of Mount Everest from sea level to its summit. In addition, much of the mountain is invisible underwater: its mass depresses the crust beneath it by another 8 km, in the shape of an inverse mountain, meaning the total height of Mauna Loa from the start of its eruptive history is about 17,170 m.
Mauna Loa is a typical shield volcano in form, taking the shape of a long, broad dome extending down to the ocean floor whose slopes are about 12° at their steepest, a consequence of its fluid lava. The shield-stage lavas that built the enormous main mass of the mountain are tholeiitic basalts, like those of Mauna Kea, created through the mixing of primary magma and subducted oceanic crust. Mauna Loa's summit hosts three overlapping pit craters arranged northeast-southwest, the first and last 1 km in diameter and the second an oblong 4.2 km × 2.5 km feature. Mokuʻāweoweo's caldera floor lies between 170 and 50 m beneath its rim and it is only the latest of several calderas that have formed and reformed over the volcano's life, it was created between 1,000 and 1,500 years ago by a large eruption from Mauna Loa's northeast rift zone, which emptied out a shallow magma chamber beneath the summit and collapsed it into its pres
