Dynamics of CO2 Emission at Mammoth Mountain, California

9909525 Kerrick了解扩散岩浆CO2脱气的动力学，自1990年以来，该动力学已导致猛犸山超过50公顷的树木死亡，这是本提案的研究重点。 我们最近记录的动态性质的CO2流出率，表明时间的变化，必须考虑到在估计总的CO2排放量为一个单独的树木杀死区或整个火山。 先前的研究，二氧化碳脱气在猛犸山没有解决潜在的错误，由于时间变化的二氧化碳排放率，但是，准确的估计二氧化碳排放率，考虑到时间的变化是强制性的监测长期变化的二氧化碳脱气率。还需要有能力在数字上过滤掉由于外部强迫而发生的CO2排放率的短期变化（而不是反映猛犸山下CO2脱气的深层来源的变化）。 因此，为了阐明通过猛犸山火山建筑物的CO2脱气的控制，并监测火山灾害，我们设计了一个全面的计划，连续监测CO2排放在猛犸山，以及阐明影响这一现象的物理和地质原理。 该项目是独一无二的，因为没有长期（超过72小时）的火山或土壤呼吸连续二氧化碳脱气研究。 因为我们正在使用新的仪器，适用于广泛的气体输送现象在非饱和区，本研究的结果是特别相关的火山和/或地热脱气和运输和CO2的外排在土壤科学，农业和生态学科。 美国国家科学基金会第98-10417号拨款使我们能够获得新的仪器和文件的动态复杂性的火山二氧化碳脱气在猛犸山，但提供有限的支持人员。 我们的临时研究表明，在猛犸山存在显着的高频变化的CO2脱气率-资金从补助金9909525将使我们能够获得一个长期的记录，将更有意义。 这笔赠款将使支持J。论文研究的驱动力短期和长期的时间变化的CO2脱气从猛犸山（使用仪器购买与美国国家科学基金会资助号98-10417）和数值模拟的气体运输在火山设置。 这项研究将通过我们与美国地质勘探局研究人员的合作，补充长谷破火山口和猛犸山活火山环境中广泛的监测仪器和基础研究。

9909525KerrickUnderstanding the dynamics of diffuse magmatic CO2 degassing, which has caused over 50 ha of tree mortality on Mammoth Mountain since 1990, is the research focus of this proposal. We have recently documented the dynamic nature of CO2 efflux rates that indicate temporal variations must be taken into account in estimating the total CO2 discharge for an individual tree-kill area or the entire volcano. Prior studies of CO2 degassing at Mammoth Mountain have not addressed potential errors due to temporal variation in CO2 efflux rates; however, accurate estimates of CO2 efflux rates which take into account temporal variability are mandatory for monitoring long-term changes in the rate of CO2 degassing. The ability to numerically filter out short-term changes in CO2 efflux rates which occur due to external forcing (rather than reflecting a change in the deep source of CO2 degassing from beneath Mammoth Mountain) is also necessary. Accordingly, to shed light on the controls of CO2 degassing through the volcanic edifice at Mammoth Mountain, and to monitor for volcanic hazard, we have designed a comprehensive program for continuously monitoring CO2 emission at Mammoth Mountain, as well as elucidating the underlying physical and geologic principles that effect this phenomenon. This project is unique as there have been no long-term (greater than 72-hour) studies of continuous CO2 degassing on volcanoes or soil respiration. Because we are using new instrumentation with applicability to a broad range of gas transport phenomena in the unsaturated zone, the results of this study are particularly relevant to volcanic and/or geothermal degassing and to the transport and efflux of CO2 in the soil science, agriculture, and ecological subdisciplines. NSF Grant No. 98-10417 allowed us to acquire novel instrumentation and document the dynamic complexity of the volcanic CO2 degassing at Mammoth Mountain, but provided limited support for personnel. Our provisional study demonstrated that significant high-frequency variability in CO2 degassing rates exists at Mammoth Mountain - funding from grant EAR-9909525 will allow us to obtain a long-term record that will be even more meaningful. This grant will enable support for J. Rogie's Ph.D. thesis research on the driving forces for short and long-term temporal changes in CO2 degassing from Mammoth Mountain (using instrumentation purchased with NSF Grant No. 98-10417) and numerical modeling of gas transport in volcanic settings. This research will compliment the broad array of monitoring instruments and basic research in the active volcanic setting of Long Valley caldera and Mammoth Mountain via our collaboration with USGS researchers.