how loud can human ears hear?
de.ci.bel 🔊a unit used to express relative difference in power or intensity, usuallybetween two accoustic or electric signlas, equal to en times the common lagarithm of the ratio of two levels.
the sound which can be observed by anyone when someone is breathing that's the lowest sound which can be observed by human ears. sound is at a low frequency which is rated as 10 db.
33. Rusting Leaves :
you may remember that day when you were walking i forest o any park you step your foot on dead and drry leaves when you smashes the rusted leaves then a sound is produced that sound is known as rusting leaves which generates a unit of 20 dB.
31. To awaken a sleeping personAwaking someone from their sleep is a kind of difficult work as they refuse to make it. but during that when they make noise like yawaning or acting of moaning that tone is about 40 dB.
An air conditioner is a system or a machine that treats air in a defined, usually enclosed area via a refrigeration cycle in which warm air is removed and replaced with cooler and more humid air. In construction, a complete system of heating, ventilation, and air conditioning is referred to as HVAC.
every one know what is Conversational talk
it is a kind of debate which people generally do but no one knows from where this talk simply turns into conversational speech.
due to some anger. yes know what i mean .
27. vaccum cleanere
Type of device which is used to remove dust particles for cleaning purpose the noise produced by a normal vacuum cleaner is 70 dB
the worlds loudest vaccum cleaner is
Giving away absolutely free of charge, with no lien, mortgage, or other encumbrance of any sort,
the undisputed world-record holder in the "loudest vacuum cleaner on the face of the Earth" category!
Act now to take advantage of this truly unique opportunity! "Wow" your friends with this incredible Hoover!
To accurately describe this fine piece of machinery, I will need to be rather wordy, so please bear with
me on this matter. Imagine you are on the runway at D/FW airport, right in front of one of the jet exhaust deflectors.
A Boeing 747-400 has just taxied on to the runway about 8 feet in front of you, and holds there, awaiting clearance for takeoff.
After a few short moments, clearance is given. The pilot keeps the brakes firmly applied as the co-pilot
gently places his hand on the throttles, then, in an instant, violently shoves all four of them forward
to maximum thrust; right up against the stops.
The ensuing cacophony resulting from the dissonance between the screaming whine of the turbines
spinning at ten bazillion RPM and the 65,000 MPH blast of air and choking exhaust blasting you into
the cold, sooty metal of the deflector is utterly deafening.
That is not how loud this vacuum is. It's louder.
A whistle is an instrument which produces sound from a stream of gas, most commonly air. It may be mouth-operated, or powered by air pressure, steam, or other means. Whistles vary in size from a small slide whistle or nose flute type to a large multi-piped church organ.
whistle of police perform more louder than a normal one.
it produces approximately
80 dB.
Snow is a kind of noise which is produced by few peoples while sleeping it is also very irritating unacepted and hard to avoid.
People do this earlier this kind of terms are observed only in old people's but nowadays it can be easily found in Gangstar also
A ball is a closed vessel in which fluid generally water is heated the flu does not necessarily boil the heated reprise fluid exists the boilers for used in various processes are heating applications including water heating Central heating Polar Bears power generation cooking and sanitation the factories who have this kind of bowlers are called ball of factories which makes noise of 100 DB.
The full name of Maria Sharapova is Maria Uri Vinay Sharapova Maria Sharapova Olympic gold medalist she born in nygan, russia but later in 1994 she bacame citizen of united states of america with her permanent resident.
she is part of wta since year 2001. she is worlds no. 1 ranked in singles by wta from 5 separate occasion for a total of 21 weeks. she is 1st lady holding the career grand slam.
Sharapova has competed on the WTA tour since 2001. She has been ranked world no.1 in singles by the WTA on five separate occasions, for a total of 21 weeks. She is one of ten women, and the only Russian, to hold the career grand slam. She is also an olympics medalist , having won silver in women's singles at the 2012 summer olympics in London. her hit is so loud that it make sound of 101 dB.
A tiny water boatman is the loudest animal on earth related to its body size a study has revealed scientist from France and Scotland recorded the aquatic animals singing the equivalent of listening to allowed or just replay was sitting in the front row.
sound generated by penis bug is105 dB
What is a noise made by a list from the stomach through the mouth which is also known as wrong sin or manner to do when you are surrounded by someone. it generally relased by unwanted co2 in stomach and released by mouth after having chilled soft drink etc.
20.michelle larcher de brito
She is a badminton player from France she 14 Single Title on the Idea store in her caree
Har grunt during play is loudest recorded tennis current grant is a voice which is produced by people during their struggling work
19.baby crying
Everyone knows that when baby cries mind goes down and upside usually when baby cries it is a sign of instinctive communication
18.trumpet
Trumpet is a brass instrument commonly used in classical and Jazz assemblies the trumpet group contains instrument with the highest register in the price family trumpet like instrument have historical e been used at signalling device and Battle or hunting with example dating back to at least 1500 BC they began to be used as musical instrument only in the 14th late and 15th early century it is used in our side of music
17.vuvuzela
It is also known as Leopard Tata it is a plastic Hona about 65 CM which is exactly 2 feet long which produces allowed monotone not typically around some models are made into parts to passage the gate storage and this design also allow speech variation many types of who was seller made by several manufacturers may produce various intensity and frequency outputs the intensity of these outputs depends on the blowing technique and pressure exerted.
16.loudest human scream
Loudest human scream is noted down by United kingdom's jailbreak in London in 2000 record is broken down by a teacher annalisa Flanagan from combo has something to shout about after a sensational voice was we entered into the Guinness Book of Records as a loudest in the world it's been well over a decade since analysis out of 128 GB
15.loudest rock concert
American heavy metal band manual is one climate of the title of love this pand in the world sitting A measurement of Itna in 1994 in Hanover however the Guinness Book of World Records list in men over as a record holder to the loudest musical performance for and Alia performance in 1984
14.fireworks
There is no need to explain 5S because everyone love them they give us I have very high thrill when we blow them apart India power generally used on festival Diwali in amount of more than tons
13.gunfire
Search from a gun organs typically creating love report that's right in the feels to hold the gun fire sir gents direct your gun fight over the Corpse of freeze chiefly military please use of gunpowder type weapons mainly Canon as a post to swap or be on net Surfers are much more reduced by using silencers and the highest noise observed by a handgun is from Magnum
12.NHRA dragsters
MHRD dragsters are one of the world's most fastest racing car with more than 600 km per hour which cannot be used by general purpose as they are having Turbo engines in them which is commonly used in airplanes drag racing is a type of motor racing in which automobile for motorcycles complete usually 2 At a time
11.space shuttle launch
Hi space shuttles was a partially visible low Earth orbit in spacecraft system operated by the US national Aeronautics and space administration as part of the space shuttle program near the space shuttles are enabled to come on earth surface after completing their mission or service but after the invention of Elon Musk who is one of the most richest person rocket space x
10.aircraft at take off
9.loudest speaker ever
8.the blue whale
The basic mechanism of sound detection is the same in all mammals, whether they live on land or in the sea. Sound waves are transformed to neural impulses in the inner ear, which are interpreted by the brain as sounds (see How do marine mammals hear sounds?
). Exposure to loud sounds can interfere with this process and cause hearing impairment or loss.
Scientists use various techniques to evaluate the effect of sound on marine mammal hearing. Hearing sensitivity can be measured using auditory testing methods similar to those used on humans and other terrestrial mammals. For more information see Hearing Sensitivity Studies.
Hearing loss in humans has been extensively studied. Scientists can use what is known about hearing loss in humans and other land mammals to help understand hearing loss in marine mammals because the basic mechanism of sound detection is the same in all mammals.. Hearing loss in mammals depends on many factors, including ncluding the hearing sensitivity of the animal in comparison to the intensity of the sound, the frequency of the sound, and the durationof exposure to the sound. Humans exposed to extremely loud sounds (e.g., rock concerts, impulse noise from gunshots, etc.) experience temporary or permanent hearing impairment. Human hearing damage can also be caused by exposure to less intense noise over long periods of time, as in a noisy work environment[3][4]. Hearing impairment does not occur if the frequency of the sound to which the animal is exposed is outside the range that the animal can hear.
7.karakatoa volcano
The 1883 eruption of Krakatoa in the Dutch East Indies (now Indonesia) began in the afternoon of Sunday, 26 August 1883 (with origins as early as May of that year), and peaked in the late morning of Monday, 27 August when over 70% of the island and its surrounding archipelago were destroyed as it collapsed into a caldera. Additional seismic activity was reported to have continued until February 1884, though reports of seismic activity after October 1883 were later dismissed by Rogier Verbeek's investigation into the eruption. The 1883 eruption was one of the deadliest and most destructive volcanic events in recorded history. At least 36,417 deaths are attributed to the eruption and the tsunamis it created. Significant additional effects were also felt around the world in the days and weeks after the volcano's eruption.
In the years before the 1883 eruption, seismic activity around the Krakatoa volcano was intense, with earthquakes felt as far away as Australia. Beginning 20 May 1883, steam venting began to occur regularly from Perboewatan, the northernmost of the island's three cones. Eruptions of ash reached an estimated altitude of 6 km (20,000 ft) and explosions could be heard in New Batavia (Jakarta) 160 km (99 mi) away. Activity died down by the end of May, and there was no further recorded activity for several weeks.
Eruptions at Krakatoa started again around 16 June with loud explosions and a thick black cloud covering the islands for five days. On 24 June, a prevailing east wind cleared the cloud, and two ash columns could be seen issuing from Krakatoa. The seat of the eruption is believed to have been a new vent or vents that formed between Perboewatan and Danan. The violence of the ongoing eruptions caused tides in the vicinity to be unusually high, and ships at anchor had to be moored with chains. Earthquakes were felt at Anyer, Banten, and ships began to report large pumice masses to the west in the Indian Ocean.[citation needed]
6.shockwave
In physics, a shock wave (also spelled shockwave), or shock, is a type of propagating disturbance. When a wave moves faster than the local speed of sound in a fluid, it is a shock wave. Like an ordinary wave, a shock wave carries energy and can propagate through a medium; however, it is characterized by an abrupt, nearly discontinuous change in pressure, temperature and density of the medium.[1][2][3][4][5][6]
For context of comparison, in supersonic flows, additional increased expansion may be achieved through an expansion fan, also known as a Prandtl-Meyer expansion fan. The accompanying expansion wave may approach and eventually collide and recombine with the shock wave, creating a process of destructive interference. The sonic boom associated with the passage of a supersonic aircraft is a type of sound wave produced by constructive interference.
Unlike solitons (another kind of nonlinear wave), the energy and speed of a shock wave alone dissipates relatively quickly with distance. When a shock wave passes through matter, energy is preserved but entropy increases. This change in the matter's properties manifests itself as a decrease in the energy which can be extracted as work, and as a drag force on supersonic objects; shock waves are strongly irreversible processes.
The abruptness of change in the features of the medium, that characterize shock waves, can be viewed as a phase transition: the pressure-time diagram of a supersonic object propagating shows how the transition induced by a shock wave is analogous to a dynamic phase transition.
When an object (or disturbance) moves faster than the information can propagate into the surrounding fluid, then the fluid near the disturbance cannot react or "get out of the way" before the disturbance arrives. In a shock wave the properties of the fluid (density, pressure, temperature, flow velocity, Mach number) change almost instantaneously. Measurements of the thickness of shock waves in air have resulted in values around 200 nm (about 10−5 in),[7] which is on the same order of magnitude as the mean free gas molecule path. In reference to the continuum, this implies the shock wave can be treated as either a line or a plane if the flow field is two-dimensional or three-dimensional, respectively.
Shock waves are formed when a pressure front moves at supersonic speeds and pushes on the surrounding air.[8] At the region where this occurs, sound waves travelling against the flow reach a point where they cannot travel any further upstream and the pressure progressively builds in that region; a high pressure shock wave rapidly forms.
Shock waves are not conventional sound waves; a shock wave takes the form of a very sharp change in the gas properties. Shock waves in air are heard as a loud "crack" or "snap" noise. Over longer distances, a shock wave can change from a nonlinear wave into a linear wave, degenerating into a conventional sound wave as it heats the air and loses energy. The sound wave is heard as the familiar "thud" or "thump" of a sonic boom, commonly created by the supersonic flight of aircraft.
The shock wave is one of several different ways in which a gas in a supersonic flow can be compressed. Some other methods are isentropic compressions, including Prandtl-Meyer compressions. The method of compression of a gas results in different temperatures and densities for a given pressure ratio which can be analytically calculated for a non-reacting gas. A shock wave compression results in a loss of total pressure, meaning that it is a less efficient method of compressing gases for some purposes, for instance in the intake of a scramjet. The appearance of pressure-drag on supersonic aircraft is mostly due to the effect of shock compression on the flow.
5.tiger pistol shrimp
The tiger pistol shrimp can grow to a size up to 4 to 5 cm, not including antennae. The body is stout and opaque. The background color of the body is yellowish white or plain yellow. The patterns drawn on the cephalothorax, abdomen and tail are irregular but symmetric, their coloration varies from light brown, brownish purple to brownish orange. The legs are banded with the same colors as the body and are covered with short bristles. The antennae are red.[1] The chelipeds are also banded, with the right being bigger and modified into a powerful weapon. By closing at extreme speed, the cheliped expels an air bubble at more than 100 kilometres per hour (62 mph) towards the prey. This action is accompanied with a loud bang. This powerful sonic weapon creates a violent shock wave which can kill or knock out prey, which could be another shrimp or a small fish passing close to the tiger pistol shrimp.
A prawn which can make a sound louder than a jet engine has been found in British waters.
Pistol shrimps - which stun their prey by snapping their claws together to create a deafening 'crack' - normally live in the sub-tropics.
Despite being less than an inch long, the creatures can emit an astonishing 218 decibels - louder than a gunshot.
Super shrimp: The pistol shrimp is only 2cm long but can make a noise louder than Concorde's sonic boom
The sound stuns small fish and crabs, allowing the shrimp to move in for the kill.
The creatures, also known as snapping shrimps, are native to the warmer waters of the Mediterranean and have only been found swimming off the coast of Britain a handful of times this century.
A pair were discovered last week near the mouth of the Helford River in Cornwall by crab fisherman Tim Bailey, 56.
They were brought to the Blue Reef Aquarium in Newquay, where staff were forced to separate them to stop them stunning each other.
Curator Matt Slater, who collected the creatures from Mr Bailey, said: 'Only a handful of this type of shrimp have ever been recorded in UK waters, although their numbers do appear to be on the rise.
'I started to think they were something special while I was driving back from Falmouth .
'I kept on hearing this cracking noise from the back of the vehicle as if someone was popping bubble wrap.
'It wasn't until we unloaded the bucket that I realised the sound was coming from the shrimps snapping their claws together.'
Ben Marshall, a scientist at the aquarium, added: 'They are among the loudest marine animals. They simply snap their claw to make a loud noise, and it's 218 decibels.'
He said the level of noise made by the shrimps was comparable with that produced by a sperm whale.
'That is 40 tonnes, and this is 2cm,' he added. 'The click of the claw stuns the victim for enough time for them to get on it and kill it - from tiny shrimp to anything planktonic.
'The noise is very instantaneous. It's not like a shotgun blast. It lasts literally a fraction of a second, but it's enough to stun the prey they're after.'
Douglas Herdson, the information officer at the National Marine Aquarium in Plymouth , said that the creatures are so loud that they can be heard by sailors.
'I have heard of yachtsmen being moored in a bay and not being able to sleep because of the noise these shrimps make,' he said.
He added that the species is likely to be seen in UK waters more often as sea temperatures rise.
The British pair may have been carried to the UK as larvae by a passing ship.
There are around 600 species of pistol shrimp worldwide. Most dig burrows and feed off small crabs and fish.
4.1 TON TNT bom
5.0 richter earthquake
| Part of a series on |
| Earthquakes |
|---|
| Types |
| Causes |
| Characteristics |
| Measurement |
| Prediction |
| Other topics |
The so-called Richter magnitude scale – more accurately, Richter's magnitude scale, or just Richter magnitude – for measuring the strength ("size") of earthquakes refers to the original "magnitude scale" developed by Charles F. Richter and presented in his landmark 1935 paper, and later revised and renamed the Local magnitude scale, denoted as "ML" or "ML". Because of various shortcomings of the ML scale most seismological authorities now use other scales, such as the moment magnitude scale (Mw), to report earthquake magnitudes, but much of the news media still refers to these as "Richter" magnitudes. All magnitude scales retain the logarithmic character of the original, and are scaled to have roughly comparable numeric values.
Development[edit]
Prior to the development of the magnitude scale the only measure of an earthquake's strength or "size" was a subjective assessment of the intensity of shaking observed near the epicenter of the earthquake, categorized by various seismic intensity scales such as the Rossi-Forel scale. In 1883 John Milne surmised that the shaking of large earthquakes might generate waves detectable around the globe, and in 1899 E. Von Rehbur Paschvitz observed in Germany seismic waves attributable to an earthquake in Tokyo.[1] In the 1920s Harry O. Wood and John A. Anderson developed the Wood-Anderson seismograph, one of the first practical instruments for recording seismic waves.[2]Wood then built, under the auspices of the California Institute of Technology and the Carnegie Institute, a network of seismographs stretching across Southern California.[3] He also recruited the young and unknown Charles Richter to measure the seismograms and locate the earthquakes generating the seismic waves.[4]
In 1931 Kiyoo Wadati showed how he had measured, for several strong earthquakes in Japan, the amplitude of the shaking observed at various distances from the epicenter. He then plotted the logarithm of the amplitude against the distance, and found a series of curves that showed a rough correlation with the estimated magnitudes of the earthquakes.[5] Richter resolved some difficulties with this method,[6] then, using data collected by his colleague Beno Gutenberg, produced similar curves, confirming that they could be used to compare the relative magnitudes of different earthquakes.[7]
To produce a practical method of assigning an absolute measure of magnitude required additional developments. First, to span the wide range of possible values Richter adopted Gutenberg's suggestion of a logarithmic scale, where each step represents a ten-fold increase of magnitude, similar to the magnitude scale used by astronomers.[8]Second, he wanted a magnitude of zero to be around the limit of human perceptibility.[9] Third, he specified the Wood-Anderson seismograph as the standard instrument for producing seismograms. Magnitude was then defined as "the logarithm of the maximum trace amplitude, expressed in microns", measured at a distance of 100 km. The scale was calibrated by defining a magnitude 3 shock as one that produces (at a distance of 100 km) a maximum amplitude of 1 micron (1 µm, or 0.001 millimeters) on a seismogram recorded by a Wood-Anderson torsion seismograph.[10] Finally, Richter calculated a table of distance corrections,[11] in that for distances less than 200 kilometers[12] the attenuation is strongly affected by the structure and properties of the regional geology.[13]
When Richter presented the resulting scale in 1935 he called it (at the suggestion of Harry Wood) simply a "magnitude" scale.[14] "Richter magnitude" appears to have originated when Perry Byerly told the press that the scale was Richter's, and "should be referred to as such."[15] In 1956 Gutenberg and Richter, while still referring to "magnitude scale", labelled it "local magnitude", with the symbol ML, to distinguish it from two other scales they had developed, the surface wave magnitude (MS) and body wave magnitude (MB) scales.[16]
2.tangusta meteor
The Tunguska event was a large explosion that occurred near the Stony Tunguska River in Yeniseysk Governorate (now Krasnoyarsk Krai), Russia, on the morning of 30 June 1908 (NS).[1][2] The explosion over the sparsely populated Eastern Siberian Taiga flattened 2,000 square kilometres (770 square miles) of forest, yet caused no known human casualties. The explosion is generally attributed to the air burst of a meteoroid. It is classified as an impact event, even though no impact crater has been found; the object is thought to have disintegrated at an altitude of 5 to 10 kilometres (3 to 6 miles) rather than to have hit the surface of the Earth.[3]
The Tunguska event is the largest impact event on Earth in recorded history. Studies have yielded different estimates of the meteoroid's size, on the order of 60 to 190 metres (200 to 620 feet), depending on whether the body was a comet or a denser asteroid.[4]
Since the 1908 event, there have been an estimated 1,000 scholarly papers (most in Russian) published on the Tunguska explosion. In 2013, a team of researchers published analysis results of micro-samples from a peat bog near the center of the affected area showing fragments that may be of meteoritic origin.[5][6]
Early estimates of the energy of the air burst range from 10–15 megatons of TNT (42–63 petajoules) to 30 megatons of TNT (130 PJ),[7] depending on the exact height of burst estimated when the scaling-laws from the effects of nuclear weapons are employed.[7][8] However, modern supercomputer calculations that include the effect of the object's momentum find that more of the energy was focused downward than would be the case from a nuclear explosion and estimate that the airburst had an energy range from 3 to 5 megatons of TNT (13 to 21 PJ).[8]
The 15-megaton (Mt) estimate represents an energy about 1,000 times greater than that of the atomic bomb dropped on Hiroshima, Japan—roughly equal to that of the United States' Castle Bravo (15.2 Mt) ground-based thermonuclear detonation on 1 March 1954, and about one-third that of the Soviet Union's Tsar Bomba explosion on 30 October 1961 (which, at 50 Mt, is the largest nuclear weapon ever detonated).[9]
It is estimated that the Tunguska explosion knocked down some 80 million trees over an area of 2,150 km2 (830 sq mi), and that the shock wave from the blast would have measured 5.0 on the Richter magnitude scale. An explosion of this magnitude would be capable of destroying a large metropolitan area,[10]but, due to the remoteness of the location, no human fatalities were officially documented. Several reports have indicated that two people may have died in the event; however, these deaths remain unofficial.[11][12][13][14] This event has helped to spark discussion of asteroid impact avoidance.
On 30 June 1908, at around 07:17 local time, Evenki natives and Russian settlers in the hills north-west of Lake Baikal observed a column of bluish light, nearly as bright as the Sun, moving across the sky. About ten minutes later, there was a flash and a sound similar to artillery fire. Eyewitnesses closer to the explosion reported that the source of the sound moved from the east to the north of them. The sounds were accompanied by a shock wave that knocked people off their feet and broke windows hundreds of kilometres away. The majority of witnesses reported only the sounds and tremors, and did not report seeing the explosion. Eyewitness accounts vary regarding the sequence and duration of the events.[citation needed]
The explosion registered at seismic stations across Eurasia. It is estimated that, in some places, the resulting shock wave was equivalent to an earthquake measuring 5.0 on the Richter magnitude scale.[15] It also produced fluctuations in atmospheric pressure strong enough to be detected in Great Britain. Over the next few days, night skies in Asia and Europe were aglow;[16] it has been theorized that this was due to light passing through high-altitude ice particles that had formed at extremely low temperatures—a phenomenon that many years later would be produced by space shuttles.[17][18] In the United States, the Smithsonian Astrophysical Observatory and the Mount Wilson Observatory observed a months-long decrease in atmospheric transparency due to an increase in suspended dust particles.[citation needed
1.mount tambora.
| Mount Tambora | |
|---|---|
| Tomboro | |
Caldera of Mount Tambora
| |
| Highest point | |
| Elevation | 2,850 m (9,350 ft) [1] |
| Prominence | 2,722 m (8,930 ft) [1][2] |
| Coordinates | 8°15′S 118°0′E |
| Geography | |
 
Mount Tambora
Location in Indonesia
| |
| Northwest: Pancasila | |
Mount Tambora (or Tomboro[3]) is an active stratovolcano in the northern part of Sumbawa, one of the Lesser Sunda Islands of Indonesia. Tambora is known for its major eruption in 1815. It was formed due to the active subduction zones beneath it, and before its 1815 eruption, it was more than 4,300 metres (14,100 feet) high, making it then one of the tallest peaks in the Indonesian archipelago.
The large magma chamber under Tambora had been drained by pre-1815 eruptions and underwent several centuries of dormancy as it refilled. Volcanic activity reached a peak that year, culminating in the eruption. With a Volcanic Explosivity Index of 7, the eruption was the most devastating in recorded history. The explosion was heard on Sumatra island, more than 2,000 kilometres (1,200 miles) away. Heavy volcanic ash rains were observed as far away as Borneo, Sulawesi, Java and Maluku islands, and the maximum elevation of Tambora was reduced from about 4,300 metres (14,100 ft) to 2,850 metres (9,350 feet). Although estimates vary, the death toll was at least 71,000 people. The eruption caused global climate anomalies in the following years, while 1816 became known as the "year without a summer" due to the impact on North American and European weather. In the Northern Hemisphere, crops failed and livestock died, resulting in the worst famine of the century.
During a 2004 excavation, archaeologists discovered the remains of a civilization destroyed and buried by the 1815 eruption. The site has remained intact beneath three metres of pyroclastic deposits and provides insight into the culture that vanished. Today, Mount Tambora is closely monitored for volcanic activity; a powerful eruption would affect millions of Indonesians. The mountain is administered by the Bima Regency in the northeast and by the Dompu Regency in the west and south.
Geographical setting[edit]
Mount Tambora is on Sumbawa island, part of the Lesser Sunda Islands. It is a segment of the Sunda Arc, a string of volcanic islands that make up the southern chain of the Indonesian archipelago.[4] Tambora forms its own peninsula on Sumbawa, known as the Sanggar peninsula. To the north of the peninsula is the Flores Sea[5] and to the south is the 86 kilometres (53 mi) long and 36 kilometres (22 mi) wide Saleh Bay.[6] At the mouth of Saleh Bay there is an islet called Mojo.[7]
Besides the seismologists and vulcanologists who monitor the mountain's activity, Mount Tambora is an area of interest to archaeologists and biologists. The mountain also attracts tourists for hiking and wildlife activities,[8] though in small numbers.[9] The two nearest cities are Dompu and Bima. There are three concentrations of villages around the mountain slope. At the east is Sanggar village, to the northwest are Doro Peti and Pesanggrahan villages, and to the west is Calabai village.[10]
There are two routes of ascent to the caldera. The first begins at Doro Mboha village on the southeast of the mountain and follows a paved road through a cashew plantation to an elevation of 1,150 metres (3,770 ft). The road terminates at the southern part of the caldera, which at 1,950 metres (6,400 ft) is reachable only by hiking.[10]This location is only one hour from the caldera, and usually serves as a base camp from which volcanic activity can be monitored. The second route starts from Pancasila village at the northwest of the mountain and is only accessible on foot.[10] The 16 kilometres (9.9 mi) hike from Pancasila at 740 metres (2,430 ft) elevation to the caldera of the volcano takes approximately 14 hours with several stops (pos) en route to the top. The trail leads through dense jungle with wildlife as Elaeocarpus batudulangii, Asian water monitor, reticulated python, hawks, orange-footed scrubfowl, pale-shouldered cicadabird(Coracina dohertyi), brown and scaly-crowned honeyeater, yellow-crested cockatoo, yellow-ringed white-eye, helmeted friarbird, wild boar, Javan rusa and crab-eating macaques.[11] Poison ivy, a rash-producing plant locally called jelatang, litters the trail towards the caldera.
Geological history[edit]
Formation[edit]
Tambora is located 340 kilometres (210 mi) north of the Java Trench system and 180 to 190 kilometres (110 to 120 mi) above the upper surface of the active north-dipping subduction zone. Sumbawa Island is flanked to the north and south by oceanic crust.[12] The convergence rate is 7.8 centimetres (3.1 in) per year.[13] The formation of Tambora is estimated to have begun around 57,000 years before present (BP),[6] while a 2012 study reports an argon age of 43 ka for the first pre-caldera lava flows.[14] The formation of Tambora drained a large magma chamber pre-existing under the mountain. The Mojo islet was formed as part of this geological process in which Saleh Bay first appeared as a sea basin about 25,000 years BP.[6]
A high volcanic cone with a single central vent formed before the 1815 eruption, which follows a stratovolcano shape.[15] The diameter at the base is 60 kilometres (37 mi).[4] The volcano frequently erupted lava, which descended over steep slopes.[15] Tambora has produced trachybasalt and trachyandesite rocks which are rich in potassium. The volcanics contain phenocrysts of apatite, biotite, clinopyroxene, leucite, magnetite, olivine and plagioclase, with the exact composition of the phenocrysts varying between different rock types.[4] Orthopyroxene is absent in the trachyandesites of Tambora.[16] Olivine is most present in the rocks with less than 53 percent SiO2, while it is absent in the more silica-rich volcanics, characterised by the presence of biotite phenocrysts.[17] The mafic series also contain titanium magnetite and the trachybasalts are dominated by anorthosite-rich plagioclase.[18] Rubidium, strontium and phosphorus pentoxide are especially rich in the lavas from Tambora, more than the comparable ones from Mount Rinjani.[19] The lavas of Tambora are slightly enriched in zircon compared to those of Rinjani.[20]
The magma involved in the 1815 eruption originated in the mantle and was further modified by melts derived from subducted sediments, fluids derived from the subducted crust and crystallization processes in magma chambers.[14] 87Sr86Sr ratios of Mount Tambora are similar to those of Mount Rinjani, but lower than those measured at Sangeang Api.[12] Potassium levels of Tambora volcanics exceed 3 weight percent, placing them in the shoshonite range for alkaline series.[21]
Since the 1815 eruption, the lowermost portion contains deposits of interlayered sequences of lava and pyroclastic materials. Approximately 40% of the layers are represented in the 1-to-4 m-thick (3.3-to-13.1 ft) lava flows.[15] Thick scoria beds were produced by the fragmentation of lava flows. Within the upper section, the lava is interbedded with scoria, tuffs, pyroclastic flows and pyroclastic falls.[15] Tambora has at least 20 parasitic cones[13] and lava domes, including Doro Afi Toi, Kadiendi Nae, Molo and Tahe.[3] The main product of these parasitic vents is basaltic lava flows.[13]
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