Bolivia not only offers the geographer and the geologist a fascinating case study; it also offers the traveller a wealth of different sceneries, landscapes and geological ‘hotspots’ to visit and explore.
The Andes stretch in a broad arc across western Bolivia, forming the second largest mountain range in the world. They were the result of two major tectonic plates colliding over 70 million years ago. The regions geology is far from static though, and the result is earthquakes and the occasional lava spurt from one of the region’s many volcanoes.
To the west of Bolivia along the Peruvian border two major tectonic plates are converging. The continental South American plate is moving westwards on top of the Oceanic Nazca plate. The boundary between these two plates is known as a ‘subduction zone’ and is the source of tremendous earthquake activity. Earthquakes release energy that spreads through the various layers of the earth. This energy radiates outwards ‘like the waves from a pebble thrown into a pond’.
The Altiplano experiences the majority of regional earthquakes: these are localized tremors which occur frequently. Larger scale earthquake activity is less common and causes more widespread devastation. In the last decade there have been less than 5 of these earthquakes; the most documented occurring on June 9th 1994 near La Paz with a magnitude of 8.2 on the Richter scale. On May 22nd 1998 two earthquakes measuring 5.9 and 6.8 on the Richter scale hit the region 50km north-west of Cochabamba. The resulting devastation led to emergency aid being donated by the Japanese government.
The Andean mountains which run through Bolivia from Southwest Peru to Chile consist of both active and extinct volcanoes. In Bolivia there are currently two active volcanoes: Volcan Ollague and Uturuncu.
Volcan Ollague is situated to the south-west of the Salar de Uyuni in the Laguna region about 20 km from the Chilean border. This impressive ‘glowing red’ cone stands at 5870m high and can be viewed when travelling in the Salar. Its active status was discovered recently when smoke was seen to be emerging from a small vent on one side.
Uturuncu is also situated in the south-west of Bolivia on the Chilean/Argentinean border. In 2003 scientists discovered that this volcano was active when taking measurements of the ‘fumarole field’ and sulphur production. The volcano, which was previously thought to be dormant by the local people, was named Uturuncu which means ‘Sleeping Tiger’ in Quechua. Although this sleeping volcano has been quietly active for sometime, it is now known to be “vertically bulging about one inch per year” indicating that the magma under the volcano is still active.
Both of these volcanoes in Bolivia have only recently been discovered to be active and therefore volcanic hazards are a growing threat. Greater geophysical monitoring has occurred and continues to be necessary, so on your travels in this ever-changing land you may need to watch out!
The historical formation of gold, silver and natural gas through the compression of lake sediment in Bolivia continues to provide income to the country today, both through extraction and the attraction it provides for tourists.
In the eastern lowlands and the Amazon River basin the discovery of oil and natural gas have led to increased population of the area as people moved to exploit these natural resources. Today these resources continue to provide a great deal of employment, but natural gas in particular causes much political controversy (check our update on the gas issue for the latest developments).
Gold and silver mining in Bolivia have both been important since pre-Inca times over 1000 years ago. Mining of these metals continues to be Bolivia’s most important industry and accounts for approximately 50% of its foreign exchange. Foreign investment in the extraction of all natural resources has increased without governmental controls. This is now having a detrimental effect on the environment and causing soil erosion.
Bolivia - The facts:
Total Area: 1,098,580 km².
Land Boundaries: Argentina, Brazil, Chile, Paraguay, Peru
Land Uses: Arable 2%, Permanent pastures 24%, Forests and Woodland 53%, Other 21%
Natural Resources: tin, natural gas, petroleum, zinc, tungsten, antimony, silver, iron, lead, gold, and timber
Climate: Varies with altitude - humid and tropical to cold and semiarid
Three Geographical areas: Andes Mountains with highland plateau (Altiplano), semi-tropical Yungas with temperate valleys and tropical lowlands including the plains of the Amazon basin