The destruction wrought by the 1985 eruption was partially due to the fact that scientists vacillated over whether or not to evacuate the area. Nevertheless, a group of scientists informed them that they faced eminent and almost certain death. The people in Armero assumed that because the volcano had not erupted in 100 years, it had no reason to erupt so abruptly. Scientists later looked back to the hours before the eruption and noticed that several long period earthquakes had occurred. Long-period earthquakes are those which start out strong and then die down very slowly. Volcanologist Bernard Chouet said that these earthquakes occurred in the final hours before an eruption. According to Chouet, "the volcano was screaming 'I'm about to explode'," but scientists at the time doubted his theory.
On November 13, 1985, at 9:08 pm, Nevado del Ruiz erupted; ejecting dacitic tephra more than 30 kilometers into the atmosphere. The amount of magma erupted from the volcano was 3% of that from Mount St. Helens in 1980. The eruption reached Volcanic Explosivity Index 3. The material ejected was described by scientists as "unusually rich in sulfur dioxide".
Pyroclastic flows melted ice and snow at the summit, forming 4 thick lahars that rushed down several river valleys. As most lahars do, the mudflows began as flows of water, sand, and gravel, and mixed with clay along the way. The lahars were up to thick and six feet deep (2 m) and traveled more than .
The lahars destroyed many houses and towns. The town of Armero was completely covered by debris, killing approximately 21,000 people (three-fourths of the population), as well as affecting 13 other villages. The eruption caused an estimated 23,000 deaths, 5,000 injuries, and destroyed more than 5,000 homes. This was the second deadliest volcanic disaster in the 20th century, ousted only by the 1902 eruption of Mount Pelee, and the fourth deadliest eruption in recorded history. In addition, it was the deadliest lahar in recorded history, and Colombia's worst natural disaster.
The disaster gained some major international notoriety due in part to a photograph taken by photographer Frank Fournier, of a young girl named Omayra Sánchez who was trapped beneath rubble for three days before she died. In response to the eruption, the USGS Volcano Crisis Assistance Team was formed in 1986, and the Volcano Disaster Assistance Program.
The volcano erupted again in 1988 and 1991.
The eruption cost Colombia 7.7 billion dollars, about 20% of the country’s GNP for the year.
A lack of preparation contributed to the high death toll. Armero had been built directly on old mudflows and authorities ignored a hazard-zone map which showed the potential damage to the town if lahars were to avalanche down the mountain. Habitants were also told to stay inside and avoid the falling ash, not thinking the mudflows would bury them. Dr. Stanley Williams of Louisiana University said that following the eruption, "With the possible exception of Mount St. Helens in the state of Washington, no other volcano in the Western Hemisphere is being watched so elaborately."
In April 2008, the Nevado del Huila volcano erupted, and thousands were evacuated. Volcanologists were worried that this could be another "Nevado del Ruiz". Hundreds of these eruptions have had huge evacuation numbers for similar reasons.
Survivors who ran to other towns in the area were gradually housed in new government schemes. Armero was not rebuilt because the old lahar traces were discovered, and the Colombian government declared the site "holy ground" so that no one would ever suffer again like Armero.
Now a new system can detect lahars, giving people more warning to evacuate before they happen. The system involves the use of Acoustic Flow Monitors (AFM) which analyze ground shaking that could result in a lahar. These AFMs are placed in the volcano and warn officials if there is a high amount of shaking. These devices were tested on Mount Rainier in the United States.
The glaciers of Nevado del Ruiz were formed slowly over hundreds of years. Because of global warming, the glaciers are starting to melt. Since Ruiz became well-known after its eruption in 1985, scientists and government officials in Colombia are worried the glaciers might melt completely.
The stratovolcano is in the Pacific Ring of Fire, an area of the earth's crust where the land is unstable. It encircles the Pacific Ocean, and houses some of the world's most active volcanoes. The volcano is the northernmost of several Colombian stratovolcanoes in the Andean Volcanic Belt of western South America. The Andean volcanic belt was produced by the eastward subduction of the oceanic Nazca plate beneath the South American continental plate. Normally, these type of stratovolcanoes generate explosive Plinian eruptions with associated pyroclastic flows that can melt snow and glaciers near the summit, thus producing devastating lahars.
The volcano is part of the Ruiz-Tolima volcanic massif (or Cordillera Central), a group of five different icy stratovolcanoes.
Tao
Tao (Pinyin Dào ) is a metaphysical concept found in Taoism, Confucianism, and more often in ancient Chinese philosophy. The Chinese character translates as "way," "path," or "route,". In Taoism, the Tao was the origin of the whole universe. Taoists believe that the "myriad things", or everything in the universe from animals to materials to ideas, originally came from the Tao, and when something disappears, it's energy (or "qi") goes back to the Tao to be absorbed and re-birthed in a different form.
The Tao is a cosmic force that can't be named or described, which is the natural harmony between all living things, and the way they all move together. Taoists thought that if someone "forgot themselves", and let go of intentions, they would be able to "move effortlessly" (wu wei, or "non-action"), and be in harmony with the Tao, like the animals, plants, and everything else. This harmony is the ultimate goal of Taoism.
Vitaceae
Vitaceae are a family of dicotyledonous flowering plants including the grape and Virginia creeper. The family name comes from the genus "Vitis". The name sometimes appears as Vitidaceae, but Vitaceae is a conserved name and therefore has priority over both Vitidaceae and another name sometimes found in the older literature, Ampelidaceae.
The relationships of Vitaceae are unclear and the family does not appear to have any close relatives. In the Cronquist system, the family was placed near the family Rhamnaceae in order Rhamnales. The family was placed in the Rosid clade, but not classified in an order, by the Angiosperm Phylogeny Group (APG). The Angiosperm Phylogeny Web places Vitaceae in its own order, Vitales. Recent phylogenetic analyses support Vitaceae as the sister-group to all other rosids (Jansen et al. 2006).
Most Vitis species have 38 chromosomes (n=19), but 40 (n=20) in subgenus Muscadinia, while Ampelocissus, Parthenocissus, and Ampelopsis also have 40 chromosomes (n=20) and Cissus has 24 chromosomes (n=12).
The family is economically important as grapes (Vitis species) are an important fruit crop and, when fermented, produce wine.
Species of the genus Tetrastigma serve as hosts to parasitic plants in the family Rafflesiaceae.
Leea, sometimes classified in its own family, Leeaceae, is included in Vitaceae by the APG and the Angiosperm Phylogeny Web.
Vitis
Vitis is a genus of about 60 species of vining plants in the flowering plant family Vitaceae. The genus is made up of species most often found in the Northern hemisphere. It is economically important as the source of grapes, both for direct consumption of the fruit and for fermentation to produce wine. The cultivation of grapevines is called viticulture. A farm or garden where grapes are grown is a vineyard.
Smiley Smile
Smiley Smile is the twelfth studio album by The Beach Boys. It was released in 1967.
Sulfur dioxide