Invisible CO2 gas killing trees at Mammoth Mountain, California

Abstract

S ince 1980, scientists have monitored geologic unrest in Long Valley Caldera and at adjacent Mammoth Mountain, California. After a persistent swarm of earthquakes beneath Mammoth Mountain in 1989, geologists discovered that large volumes of carbon dioxide (CO 2) gas were seeping from beneath this volcano. This gas is killing trees on the mountain and also can be a danger to people. The U.S. Geological Survey (USGS) continues to study the CO 2 emissions to help protect the public from this invisible potential hazard. Invisible CO 2 Gas Killing Trees at Mammoth Mountain, California Areas of dead and dying trees Areas of dead and dying trees at Mammoth Mountain volcano total more than 100 acres. In 1990, the year after a persistent swarm of small earthquakes occurred beneath the volcano, U.S. Forest Service rangers first noticed areas of tree kill. When U.S. Geological Survey scientists investigated, they discovered that the trees are being killed by high concentrations of CO 2 gas in the soil. The seepage of CO 2 gas from below Mammoth Mountain and the continued occurrence of local earthquakes are signs of the ongoing geologic unrest in the area. The upper part of the 11,053-foot-high volcano (above 9,500 feet) is shown in darker shades of green.

Remote sensing of CO2 leakage from geologic sequestration projects

“…Multiple studies investigating seepages of deepearth hydrocarbon gases provide proof of concept that there is a detectable vegetative response associated with gas influxes to the soil, indicating the viability of such detection for a carbon sequestration project (Noomen et al, 2008(Noomen et al, , 2012. It is hypothesized that excess CO 2 in the subsurface displaces other essential gases, causing the plant to die (Fitter et al, 1995;Sorey et al, 2000). Alternatively, the preponderance of CO 2 will cause a plant to close its stomatal openings (as with the thermal response), resulting in a complete shutdown of plant transpiration with consistent high CO 2 concentrations (Field et al, 1995).…”

Anatomy of thermal unrest at a hydrothermal system: Case study of the 2021-2022 crisis at Vulcano

“…Hydrothermal systems associated with non-eruptive, fumarolic degassing are liable to generate phreatic eruptions with little warning (e.g., Kato et Whether unrest leads to explosive activity or not, geophysical signals recorded for restless systems can provide insights into processes operation, in and above the hydrothermal system (Montalto 1994; Mannen et al 2018;Moretti et al 2020;Girona et al 2021). In addition, even unrest that does not lead to explosive activity presents hazards as sometimes testi ed by high contents of toxic gases in the ambient air, as for example at Mammoth Mountain (USA) during 1989 (Sorey et al 2000).…”

Impacts of Carbon Dioxide Gas Leaks from Geological Storage Sites on Soil Ecology and Above-Ground Vegetation

“…While plants in general are known to be more tolerant to elevated CO 2 gas, persistent leaks from geological storage sites may lead to accumulation of CO 2 gas in soil (near and sub surface). This may suppress root respiration, alter plant water / nutrient uptake capacity by altering soil pH towards acidity and ultimately affect aboveground biomass (Celia et al, 2002;Cook et al, 1998;Gahrooee, 1998;Miglietta et al, 1998;Sorey et al, 2000;Sowerby et al, 2000;Stephens & Hering, 2002). There are many studies where forest trees or perennial vegetation mortality from naturally occurring active volcanoes emitting CO 2 gas into atmosphere have also been documented (e.g.…”