Nevado del Ruiz is the northernmost volcano of the Andean Volcanic Belt, lying about 129 kilometers (80 mi) west of Bogotá in the Tolima Department of Colombia. It is a stratovolcano, composed of many layers of lava alternating with hardened volcanic ash and other pyroclastic rocks. Nevado del Ruiz has been active for about two million years, since the early Pleistocene or late Pliocene epoch, with three major eruptive periods. The current volcanic cone formed during the "present" eruptive period, which began 150 thousand years ago. Nevado del Ruiz usually generates Plinian eruptions, which produce swift-moving currents of hot gas and rock called pyroclastic flows. These eruptions often cause massive lahars (mud and debris flows), which pose a threat to human life and the environment. On November 11, 1985, a small eruption produced an enormous lahar that buried and desolated the town of Armero in Tolima Department, causing an estimated 23,000 deaths. This event later became known as the Armero tragedy—the deadliest lahar in recorded history. The volcano is part of Los Nevados National Park, which also contains several other volcanoes. The summit of Nevado del Ruiz is covered by large glaciers, although these have retreated significantly since 1985 due to atmospheric warming.

Read the rest of this article: http://en.wikipedia.org/wiki/Nevado_del_Ruiz

_______________________________ Today's selected anniversaries:

711:

According to estimations made by historian David Levering Lewis, Muslim Arabs and Berbers led by Tariq ibn Ziyad defeated Roderic and the Visigoths at the Battle of Guadalete. http://en.wikipedia.org/wiki/Battle_of_Guadalete

1848:

The two-day Women's Rights Convention, the first women's rights and feminist convention held in the United States, opened in Seneca Falls, New York. http://en.wikipedia.org/wiki/Seneca_Falls_Convention

1870:

A dispute over who would become the next Spanish monarch following the deposition of Isabella II during the 1868 Glorious Revolution led France to declare war on Prussia. http://en.wikipedia.org/wiki/Franco-Prussian_War

1916:

World War I: Australian forces engaged the Germans at the Battle of Fromelles in France, described as "the worst 24 hours in Australia's entire history" since 5,533 Australian soldiers were eventually killed, wounded or taken prisoner in the failed operation. http://en.wikipedia.org/wiki/Battle_of_Fromelles

1947:

Burmese nationalist Aung San and six members of his newly-formed cabinet were assassinated during a cabinet meeting. http://en.wikipedia.org/wiki/Aung_San

_____________________________ Wiktionary's word of the day:

legwork (n): 1. (idiomatic) Work, especially research, that involves significant walking, travel, or similar effort

2. Skillful or vigorous use of the legs, as in dance or sports http://en.wiktionary.org/wiki/legwork

___________________________ Wikiquote quote of the day:

Everyone has talent at twenty-five. The difficulty is to have it at fifty. --Edgar Degas http://en.wikiquote.org/wiki/Edgar_Degas