Crater Lake,
Rincon de la Vieja Volcano

Crater Lake at Rincon de la Vieja (Photo: )

LOCATION: Rincon de la Vieja Volcano
                     Northwest Costa Rica

VOLCANIC FORM: Quaternary Stratovolcano
 
 

Latitude	Longitude	Elevation	Lake diameter	Temp. (oC)	pH
10o 50' N	o ' W	1750 m	252 m	38	~ 0

 
Aerial View of the Summit Craters at Rincon de la Vieja
Rincon de la Vieja is situated in the Guanacaste Geothermal Province of northwestern Costa Rica, and is the only active volcano of the 5 that form the Guanacaste mountain chain.  The Active Crater at Rincon de la Vieja contains a warm, acidic crater lake, whose waters consist of a chloride-sulfate brine with elevated concentrations of calcium, magnesium, aluminum, iron, manganese, copper, zinc, fluoride, and boron.
 
 
 
 
 

RECENT ACTIVITY:

• The Dead Zone - Acid rain has carved a dramatic scene into the southwestern flank of Rincon de la Vieja.  Atmospheric moisture  mixes with crater lake vapors to produce rainwater so acidic that it has devegetated the southwestern flank of the volcano and caused deep erosion of the mountainside.

• November 1995 - Phreatic eruption ejected part of the Crater Lake and produced lahars that travelled down the Rio Penjamo.

• Similar phreatic eruptions accompanied by lahar production occurred in 1991, 1983, 1967, 1966, 1922.

A NATURAL SOURCE OF ENERGY

    Rincon de la Vieja from a Distance

Through progressive science and technology, Costa Rica has found a way to harness the geothermal energy of the Guanacaste Geothermal Province.  In the early 1990's, a power plant was constructed near the south flank of Miravalles, the central volcano of the Guanacaste system.  This 55 MW power plant is fueled by the energy of a 2400C thermal reservoir beneath Miravalles volcano.  Studies have shown that similar geothermal features exist at Rincon de la Vieja (Giggenbach and Soto, 1992), and the possibility for geothermal exploitation may exist there as well.

A NATURAL SOURCE OF DESTRUCTION?

The hydrothermal system at Rincon de la Vieja appears similar to those at many active stratovolcanos that host crater lakes.  An acidic crater lake and several areas of thermal springs and boiling pools have become the surficial expressions of a hot magma body underlying the volcano.

Despite its similarities to other systems, the interaction of the volcano's morphology with its hydrology has produced a distinct hazard at Rincon.  Except for the north flank, all sides of the Active Crater are supported by stable volcanic ridges.  In contrast, the north flank of the Active Crater is extremely steep, with "vertical to undercut internal crater walls and outer flank dips approaching 30⁰" (Kempter & Rowe, 19__).  Thermal springs discharge from the north flank of the Active Crater and show similar chemistry to the waters of the crater lake.  The chemical similarity between the crater lake and the springs at the north flank point to seepage of crater lake waters through the volcanic strata of the north flank and discharge at the springs.  Hypotheses exist that acid fluids migrating through the northern flank are currently dissolving the rock and weakening the slope.  Eventually, such dissolution could lead to crater collapse and a deluge of crater lake waters down the northern slope of Rincon de la Vieja (Kempter & Rowe, 19__).
 

BACK TO SOUTH AMERICA INDEX
BACK TO HOME

1. Title: Leakage of Active Crater Lake Brine through the North Flank at Rincon de la Vieja Volcano, northwest Costa Rica: Implications for Crater Collapse.
Authors: Kempter, K.A.and Rowe, G.L.
Source:
Volume:
Year:

2. Title: Isotopic and chemical composition of water and steam discharges from volcanic-magmatic-hydrothermal systems of the Guanacaste Geothermal Province, Costa Rica.
Authors: Giggenbach, W and Soto, R.C.
Source: Applied Geochemistry
Volume: 7
Year: 309 - 332

3.  Title:
Authors:
Source:
Volume:
Year:

4.  Title:
Authors:
Source:
Volume:
Year: