Everything about Mount Tambora totally explained
Mount Tambora (or
Tomboro) is an active
stratovolcano, also known as a
composite volcano, on
Sumbawa island,
Indonesia. Sumbawa is flanked both to the north and south by
oceanic crust, and Tambora was formed by the active
subduction zones beneath it. This raised Mount Tambora as high as 4,300 m (14,000 ft), making it one of the tallest peaks in the Indonesian archipelago, and drained off a large
magma chamber inside the mountain. It took centuries to refill the magma chamber, its volcanic activity reaching its peak in April 1815.
Tambora erupted in
1815 with a rating of seven on the
Volcanic Explosivity Index, making it the largest eruption since the
Lake Taupo eruption in
AD 181. The explosion was heard on
Sumatra island (more than 2,000 km or 1,200 mi away). Heavy
volcanic ash falls were observed as far away as
Borneo,
Sulawesi,
Java and
Maluku islands. The death toll was at least 71,000 people, of whom 11,000–12,000 were killed directly by the eruption; The eruption created global climate anomalies;
1816 became known as the
Year Without a Summer because of the effect on North American and European weather.
Agricultural crops failed and
livestock died in much of the
Northern Hemisphere, resulting in the worst
famine of the
19th century. They were kept intact beneath the 3 m (10 ft) deep
pyroclastic deposits. At the site, dubbed the
Pompeii of the East, the artifacts were preserved in the positions they'd occupied in 1815.
Geographical setting
Mount Tambora is located on
Sumbawa Island, part of the
Lesser Sunda Islands. It is a segment of the
Sunda Arc, a string of
volcanic islands that form the southern chain of the Indonesian
archipelago. Tambora forms its own
peninsula on Sumbawa, known as the Sanggar peninsula. At the north of the peninsula is the
Flores Sea, and at the south is the 86 km (53.5 mi) long and 36 km (22 mi) wide Saleh Bay. At the mouth of Saleh Bay there's an islet called Mojo.
Besides the
seismologists and
vulcanologists who monitor the mountain's activity, Mount Tambora is an area of scientific studies for archaeologists and
biologists. The mountain also attracts tourists for
hiking and wildlife activities. 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.
There are two ascent routes to reach the
caldera. The first route starts from Doro Mboha village at the southeast of the mountain. This route follows a paved road through a
cashew plantation until it reaches 1,150 m (3,800 ft)
above sea level. The end of this route is the southern part of the caldera at 1,950 m (6,400 ft), reachable by means of a hiking track. This location is usually used as a base camp to monitor the volcanic activity, because it only takes one hour to reach the caldera. The second route starts from Pancasila village at the northwest of the mountain. Using the second route, the caldera is accessible only by foot. The convergence rate is 7.8 cm/year (3 in/year). The existence of Tambora is estimated to have begun around 57,000 years ago. The diameter at the base is 60 km (37 mi). Their estimated dates are 3910 BC ± 200 years, 3050 BC and AD 740 ± 150 years. They were all explosive central vent eruptions with similar characteristics, except the lattermost eruption had no
pyroclastic flows.
In 1812, Mount Tambora became highly active, with its eruptive peak in the catastrophic explosive event of April 1815.
Mount Tambora is still
active. Minor lava domes and flows have been extruded on the caldera floor during the 19th and 20th centuries. On
April 5 1815, a moderate-sized eruption occurred, followed by
thunderous detonation sounds, heard in
Makassar on
Sulawesi (380 km or 236 mi), Batavia (now
Jakarta) on
Java (1,260 km or 783 mi), and
Ternate on the
Molucca Islands (1400 km or 870 mi). What was first thought to be sound of firing guns was heard on 10–11 April on
Sumatra island (more than 2,600 km or 1,615 mi away). On the morning of
6 April,
volcanic ash began to fall in
East Java with faint detonation sounds lasting until
10 April.
At about 7 p.m. on
10 April, the eruptions intensified. It had roughly four times the energy of the 1883
Krakatoa eruption. An estimated 100 km³ (38.6 mi³) of pyroclastic
trachyandesite was ejected, weighing approximately 1.4×10
14 kg. Before the explosion, Mount Tambora was approximately 4,300 m (14,000 ft) high,
The 1815 Tambora eruption is the largest observed eruption in recorded history (see Table I, for comparison). Petroeschevsky (1949) estimated about 48,000 and 44,000 people were killed on Sumbawa and Lombok, respectively. Several authors use Petroeschevsky's figures, such as Stothers (1984), who cites 88,000 deaths in total.
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