Energy budget analysis for Poás crater lake: implications for predicting volcanic activity

Water, heat and chloride budgets of the crater lake, Yugama at Kusatsu-Shirane volcano, Japan.

“…The coincidence of these events suggests a cause which is common for the two observations. Fracture formation in the surround ing region of a cooling magma may be the cause as inferred for the Pods crater lake where Brown et al (1989) suggested that fracture formation re sulted in the release of magmatic volatiles to the overlying hydrothermal system. A circulating hy drothermal fluid in the fractures may heat the wall rock and thus demagnetize it.…”

“…Therefore, the input fluid from point B can be either water vapor, liquid water or a mixture Ta), (13) where k (kJ m-2 deg 1 day') is an unknown pa rameter including the effect of wind speed and air humidity. According to Brown et al (1989), the conductive and latent heat loss from a lake surface are, Eevap = 86400 Slake LE(gw qa )u (14) and Econd = 86400S1akepCpE(Tw Ta )u, (15) respectively, where L is the latent heat of vapor ization of water (2400 kJ kg-1 at room tempera ture), E is the average particle flux (no dimen sion), u is the friction velocity (m s-1), p is the air density (0.92 kg m-3 at 2000 m altitude at 10°C), q,,, is vapor density of the saturated air at lake water temperature, qa is the vapor density of am bient air (kg m-3), and Cp represents the specific heat of water-saturated air at 10°C (1.013 kJ kg -1 deg 1) (Brown et al, 1989 (20). From the averaged temperatures, the ratio was calculated and shown in Table 2.…”

“…Ohsawa et al (1993) showed a long term change in sulfur isotope ratios in the crater lake at Kusatsu-Shirane volcano. Brown et al (1989) estimated the energy output from the crater lake at Pods volcano and detected a change cor responding to the volcanic activity. Hurst et al (1991) applied a box model to the crater lake at Ruapehu volcano and deduced a heat transfer mechanism to the lake from an underlying heat source.…”

Thermal and geochemical signature of Poás Volcano, Costa Rica (MARCH 2009)

“…Hence, the temperature of a crater lake reflects the interaction between magma at depth and the volcanic hydrothermal system, and can thus be used for monitoring purposes. At several volcanoes, increases in crater lake temperatures preceded eruptive crises (e.g., Brown et al, 1989Brown et al, , 1991Oppenheimer, 1993;Ohba et al, 2000;Varekamp et al, 2001).…”

δ18O and δD variations in some volcanic lakes on the Cameroon Volcanic Line (West-Africa): generating isotopic baseline data for volcano monitoring and surveillance in Cameroon

“…Only the last two contained isotopic profiles for Lakes Nyos, Monoun and Wum without discussing their variations and controls further. The new data will assess reservoir dynamics (Brown et al, 1989;Ohba et al, 1994). These insights will enable us to understand and interpret any changes that may occur along the water column in response to an inflow of fluids with a distinct δ 18 O/δD composition.…”