The acidity of the TMLC waters (pH ~ 3) allows the emission of big amounts of CO 2 to the atmosphere, as at low pH values, the water of the lake reduces dramatically its ability to dissolve acid gas species as CO 2. The eruption ejected juvenile products, with evidence of magma mingling 46 and represented a great impact to the Philippines, as around half a million people were directly affected by the event, producing the loss of ~ 69 M$ worth of damage to infrastructure and agriculture 47.
The eruption was characterized first by a phreatic-phreatomagmatic style, producing a giant plume of volcanic ash up to ~ 15 km in the atmosphere 45, and ended with a less explosive eruption characterized by the occurrence of lava fountains. On 12 January 2020, a volcanic eruption occurred in the main crater of Taal volcano. Magmatic intrusions have been the most plausible mechanism to explain these unrests 30, 42, 43, although other authors have pointed out that magma intrusions were very unlikely after 1994 44. Taal volcano has suffered frequent periods of unrest since the eruption in 1977, characterized by increases in the seismic activity, ground deformation and gas emissions. Hydrothermal fluids, a mixture of seawater, volcanic water and meteoric water 41, feed the surface discharges of Taal volcano and produced strong hydrothermally altered areas exhibiting solfatara, fumaroles, hot springs, and gas bubbling in the TMCL. However, the detection of diffuse CO 2 degassing anomalies prior to volcanic eruptions reported are very scarce 34, 37, 38, 39, 40. During the last 25 years numerous gas geochemical studies have highlighted the importance of this type of degassing in volcanic systems 7, 8, 9, 20, 21, 22, 23, 24, 25, 26 and its great use to strengthen the geochemical monitoring program for volcanic surveillance 27, 28, 29, 30, 31, 32, 33, particularly at those volcanic areas where visible volcanic gas emissions (plume, fumaroles, etc.) either are scarce or do not exist 34, 35, 36. One of the first studies of diffuse degassing on volcanoes was about continuous soil gas H 2 monitoring at Mount St. In addition, large quantities of thermal energy are released by volcanoes through its diffuse CO 2 emission 10, 11, 12 and this type of degassing can be also a significant contributor to the subaerial global volcanic CO 2 degassing 13, 14, 15, 16.ĭiffuse volcanic degassing disturbs the chemical and isotopic composition of the soil-air and water–air interfaces at the surface environment of the volcano, producing enrichments not only of CO 2 but also of He, H 2 and other tracer gases 17, 18, 19. Volcanogenic CO 2 is released not only through preferential degassing routes in volcanoes such as fumaroles and plumes, but it could partially also percolate through the entire volcanic edifice and released to the atmosphere in a diffuse or “silent” mode” 7, 8, 9. It is also a good tracer deep of sub-surface magma degassing, since its low solubility in silicate melts at low to moderate pressure favors its early exsolution 4, 5, 6. This collaborative research was focused mainly in the monitoring of diffuse CO 2 degassing since it is the CO 2 major gas component, beside water vapor, in both volcanic-hydrothermal fluids and magmas. Following this international awareness, a collaborative geochemical monitoring research program between Philippine and Spanish scientists was established to contribute to the strengthening of volcanic surveillance of Philippine volcanoes.
0 kommentar(er)
