While rocks melted by the impact resemble volcanic rocks, they incorporate unmelted fragments of bedrock, form unusually large and unbroken fields, and have a much more mixed chemical composition than volcanic materials spewed up from within the Earth.

While many phantom islands appear never to have existed, a few ( such as, perhaps, Thompson Island or Bermeja ) may have been actual islands subsequently destroyed by volcanic explosions, earthquakes or submarine landslides, or low-lying lands such as sand banks that are no longer above water.

While the older islands have disappeared below the sea as they moved away from the mantle plume, the youngest islands, Isabela and Fernandina, are still being formed, with the most recent volcanic eruption in April 2009 where lava from the volcanic island Fernandina started flowing both towards the island's shoreline and into the centre caldera.

While other ecozones include old continental land masses or fragments of continents, Oceania is composed mostly of volcanic high islands and Coral atolls that arose from the sea in geologically recent times, many of them in the Pleistocene.

While anchored off the Galápagos, Beebe and his crew noticed volcanic activity on Albemarle Island, and set out to investigate it.

While still dominated by silicates, more primitive volcanic rocks have mineral assemblages with less silica, such as olivine and the pyroxenes.

While the oceanic crust in the Juan de Fuca plate melts under the subterranean pressure, this creates pools of molten lava that have uplifted the Cascade Range and created volcanic eruptions from time to time.

While the Yellowstone hotspot is now under the Yellowstone Plateau, it previously helped create the eastern Snake River Plain ( to the west of Yellowstone ) through a series of huge volcanic eruptions.

While the glaciation was extensive, volcanic ash from eruptive activity at Mazama Volcano has almost certainly masked contents.

While not a sophisticated actor or a flawless musician, his huge voice and volcanic renditions of the most forceful tenor roles in the Italian and French repertoires had a tremendous impact on audiences, enabling him to build a worldwide reputation as an elite performer and charge promoters on both sides of the Atlantic top-tier fees for his services.

While the island is not a volcano it is composed primarily of Miocene volcanic rocks ( basalt ) interbedded with marine sediments.

While Hillman's relationship with the Communist Party ultimately broke up in the conflict over whether to support Robert La Follette, Sr .' s candidacy for President on the Progressive Party ticket in 1924, Hillman never faced the sort of volcanic upsurge that nearly tore apart the International Ladies ' Garment Workers ' Union during this period and never undertook the wholesale purges that David Dubinsky and other leaders of the ILGWU used to stay in power.

While many of the basalts either erupted within, or flowed into, low lying impact basins, the largest expanse of volcanic units, Oceanus Procellarum, does not correspond to any known impact basin.

While Snowdonia contains a mix of volcanic rocks and sedimentary rocks of Cambrian and Ordovician age, the mountains of South Wales are mainly Devonian age Old Red Sandstone and Carboniferous Limestone and similarly aged sandstones.

While the canyons of the Colorado River confirmed his long-standing views on erosion, the volcanic regions of Wyoming, Montana and Utah supplied him with valuable data in explanation of volcanic phenomena.

While such variations have not been definitively linked to variations in Io's volcanic activity ( the ultimate source for material in the plasma torus ), this link has been established in the neutral sodium cloud.

While the high peaks themselves are all constituted of volcanic material, the mountains stand on broad uplifted area caused by a mantle plume.

While many of the planets are predominantly grasslands dotted with trees, other worlds feature wildly different terrains, such as a volcanic world and a planet almost entirely covered by water.

While they may appear to be just a spur of the Hunua Ranges, the Bombay Hills are geologically quite distinct, being mainly of volcanic origin.

While not as impressive at 1, 772 feet ( 540 m ) as other peaks, Taum Sauk and the St. Francois range are true mountains, being the result of a volcanic orogeny.

While at the Scripps Institution of Oceanography he observed the nature of the Emperor chain of seamounts that extended from the northwest end of the Hawaiian Island – Midway chain and speculated over lunch with Robert Fisher in 1953 that something must be carrying these old volcanic mountains northward like a conveyor belt.

While the impact of ash on the lake's ecosystem is predicted to be minimal, the impact of potential future erosion is not yet known.

While some 55 ionic species have been reported in fresh ash leachates the most abundant species usually found are the cations Na < sup >+</ sup >, K < sup >+</ sup >, Ca < sup > 2 +</ sup > and Mg < sup > 2 +</ sup > and the anions Cl < sup >-</ sup >, F < sup >-</ sup > and SO < sub > 4 </ sub >< sup > 2 -</ sup >.

While this ' slash and burn ' technique may describe the method for opening new land, commonly the farmers in question have in existence at the same time smaller fields, sometimes merely gardens, near the homestead there they practice intensive ' non-shifting " techniques until shortage of fields where they can employ " slash and burn " to clear land and ( by the burning ) provide fertilizer ( ash ).

While it shared similarities with St Elmo's fire, the glow experienced was from the impact of ash particles on the leading edges of the aircraft, similar to that seen by operators of sandblasting equipment.

While typically made of wood ( cornel cherry, apricot, plum, boxwood, mountain ash, etc.

While enlarging the land by 2. 4 km², it spawned 300 seismic events, hurled ash 1 km, destroyed 300 houses in the parishes of Capelo and Praia do Norte and caused the evacuation of 2, 000 people ( emigration to the US and Canada ).

While phonesthemes have mostly been identified in the onsets of words and syllables, they can have other forms. There has been some argument that sequences like "- ash " and "- ack " in English also serve as phonesthemes, due to their patterning in words that denote forceful, destructive contact (" smash ", " crash ", " bash ", etc.

While smoke condensates such as tar and ash are removed from the solution during production, the European Food Safety Authority ( EFSA ) is investigating the safety of liquid smoke as a food flavoring.

While the source of the anomalies may indeed be buried metal, brick, slag, ash, or other disturbances the buried drums could also be the source of the anomalies.

While the 100 year-old main structure was completely destroyed, inexplicably, the Guru Granth Sahib, the 1, 430 page holy book, remained unharmed, though surrounded by charred wood and ash.

While the pattern is uneven, some having gained more than others, nationalism has in fact served the Western peoples well.

While sovereignty has roots in antiquity, in its present usage it is essentially modern.

While The Space Merchants indicates, as Kingsley Amis has correctly observed, some of the `` impending consequences of the growth of industrial and commercial power '' and satirizes `` existing habits in the advertising profession '', its warning and analysis penetrate much deeper.

While all citizens share in blame for lax municipal ethics the Wagner regime has seen serious problems in the schools, law enforcement and fiscal policies.

While 2-year-olds are still gaining most of the attention at the track, green horses are starting to go a bit, and Jimmy Cruise has several that can really make it.

While many companies have done fine work in developing sales personnel, much of it has been product rather than sales training.

While the U. S. Department of Labor has a program of projecting industry and occupational employment trends and publishing current outlook statements, there is little tangible evidence that these projections have been used extensively in local curriculum planning.

While availability of mortgage money has been a factor in encouraging apartment construction, the generally high level of prosperity in the past few years plus rising consumer income are among the factors that have encouraged builders to concentrate in the apartment-building field.

While each scene has its own character and completeness it must fit into the general sequence to which it belongs.

While that national dichotomy has stymied any effort at changing the tradition of the national anthem, " America the Beautiful " continues to be held in high esteem by a large number of Americans.

) While Rotokas has a small alphabet because it has few phonemes to represent ( just eleven ), Book Pahlavi was small because many letters had been conflated — that is, the graphic distinctions had been lost over time, and diacritics were not developed to compensate for this as they were in Arabic, another script that lost many of its distinct letter shapes.

While the Ural – Altaic hypothesis can still be found in encyclopedias, atlases, and similar general references, it has not had any adherents in the linguistics community for decades.

While most everyone has an experience with anxiety at some point in their lives, as it is a common reaction to real or perceived threats of all kinds, most do not develop long-term problems with anxiety.

While authors such as Emmanuel Le Roy Ladurie, Marc Ferro and Jacques Le Goff continue to carry the Annales banner, today the Annales approach has been less distinctive as more and more historians do work in cultural history, political history and economic history.

While the 68000 family has a 32-bit design, the 68000 used in several early models is generally referred to as 16-bit.

While the civil market has had weather radar for a while, there are strict rules about using it to navigate the aircraft.

While AA has pamphlets that suggest meeting formats, groups have the autonomy to hold and conduct meetings as they wish " except in matters affecting other groups or A. A. as a whole ".

While the term — literally meaning " sailing the air "— originally referred solely to the science of operating the aircraft, it has since been expanded to include technology, business and other aspects related to aircraft.

While tanks are seen as being integral to armoured warfare, in forces with a remit of power projection deployability has always been a consideration, which conventional main battle tanks cannot provide.

While an autobiography typically focuses on the " life and times " of the writer, a memoir has a narrower, more intimate focus on his or her own memories, feelings and emotions.

While paracetamol is usually taken orally or rectally, an intravenous preparation introduced in 2002 has been shown to improve pain relief and reduce opioid consumption in the perioperative setting.

While the use of paracetamol, aspirin, ibuprofen, naproxen and other NSAIDS concurrently with weak to mid-range opiates ( up to about the hydrocodone level ) has been said to show beneficial synergistic effects by combatting pain at multiple sites of action, several combination analgesic products have been shown to have few efficacy benefits when compared to similar doses of their individual components.

While this opinion has remained popular, other views have been expressed as well.

While not all these conclusions have been accepted, it has had an enduring influence on archaeoastronomy, especially in Europe.