No abstract

The magnitude of future climate change could be moderated by immediately reducing the amount of CO entering the atmosphere as a result of energy generation and by adopting strategies that actively remove CO from it. Biogeochemical improvement of soils by adding crushed, fast-reacting silicate rocks to croplands is one such CO-removal strategy. This approach has the potential to improve crop production, increase protection from pests and diseases, and restore soil fertility and structure. Managed croplands worldwide are already equipped for frequent rock dust additions to soils, making rapid adoption at scale feasible, and the potential benefits could generate financial incentives for widespread adoption in the agricultural sector. However, there are still obstacles to be surmounted. Audited field-scale assessments of the efficacy of CO capture are urgently required together with detailed environmental monitoring. A cost-effective way to meet the rock requirements for CO removal must be found, possibly involving the recycling of silicate waste materials. Finally, issues of public perception, trust and acceptance must also be addressed.

This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research and education use, including for instruction at the authors institution and sharing with colleagues.Other uses, including reproduction and distribution, or selling or licensing copies, or posting to personal, institutional or third party websites are prohibited. and we concurrently derived SO 2 masses for more than 130 Strombolian explosions and 50 gas puffs. From this, we show erupted SO 2 masses have a variability of up to one order of magnitude, and range between 2 and 55 kg (average $ 20 kg), corresponding to a time integrated flux of 0.05 7 0.01 kg s À 1 . Our experimental constraints on individual gas puff mass (0.03-0.42 kg of SO 2 , averaging 0.19 kg) are the first of their kind, equating to an emission rate ranging from 0.02 to 0.27 kg s À 1 . On this basis, we conclude that puffing is two times more efficient than Strombolian explosions in the magmatic degassing process, and that active degassing (explosions þpuffing) accounts for $ 23% (ranging from 10% to 45%) of the volcano's total SO 2 flux, e.g., passive degassing between the explosions contributes the majority ( $ 77%) of the released gas. We furthermore integrate our UV camera gas data for the explosions and puffs, with independent geophysical data (infrared radiometer data and very long period seismicity), to offer key and novel insights into the degassing dynamics within the shallow conduit systems of this open-vent volcano.

Ultraviolet camera technology offers considerable promise for enabling 1 Hz timescale acquisitions of volcanic degassing phenomena, providing two orders of magnitude improvements on sampling frequencies from conventionally applied scanning spectrometer systems. This could, for instance enable unprecedented insights into rapid processes, such as strombolian explosions, and non-aliased corroboration with volcano geophysical data. The uptake of this technology has involved disparate methodological approaches, hitherto. As a means of expediting the further proliferation of such systems, we here study these diverse protocols, with the aim of suggesting those we consider optimal. In particular we cover: choice and set up of hardware, calibration for vignetting and for absolute concentrations using quartz SO 2 cells, the retrieval algorithm and whether one or two filters, or indeed cameras, are necessary. This work also involves direct intercomparisons with narrowband observations obtained with a scanning spectrometer system, employing a differential optical absorption spectroscopic evaluation routine, as a means of methodological validation.

[1] In contrast to the seismic and infrasonic energy released from quiescent and erupting volcanoes, which have long been known to manifest episodes of highly periodic behavior, the spectral properties of volcanic gas flux time series remain poorly constrained, due to a previous lack of hightemporal resolution gas-sensing techniques. Here we report on SO 2 flux measurements, performed on Mount Etna with a novel UV imaging technique of unprecedented sampling frequency (0.5 Hz), which reveal, for the first time, a rapid periodic structure in degassing from this target. These gas flux modulations have considerable temporal variability in their characteristics and involve two period bands: 40-250 and 500-1200 s. A notable correlation between gas flux fluctuations in the latter band and contemporaneous seismic root-mean-square values suggests that this degassing behavior may be generated by periodic bursting of rising gas bubble trains at the magma-air interface.

Here we present a novel spectroscopic approach to capturing, with unprecedented time resolution and accuracy, volcanic SO2 fluxes. This is based on two USB2000 spectrometers, coupled to cylindrical lens telescopes, each collecting light which has transited horizontal sections of the rising plume. We report on field data from Stromboli volcano, in which the entire emission rate from the volcano was measured, as well as flux signatures associated with individual crater explosions. The latter were integrated with seismic and thermal data, demonstrating correlations in both cases, and representing the first such geophysical‐geochemical data corroboration on this timescale. Such a holistic empirical capability could significantly expedite our understanding of explosive volcanic processes.

Substantial carbon drawdown potential from enhanced rock weathering in the United Kingdom. Nature Geoscience (Early access).For guidance on citations see FAQs.

The UV camera is becoming an important new tool in the armory of volcano geochemists to derive high time resolution SO 2 flux measurements. Furthermore, the high camera spatial resolution is particularly useful for exploring multiple-source SO 2 gas emissions, for instance the composite fumarolic systems topping most quiescent volcanoes. Here, we report on the first SO 2 flux measurements from individual fumaroles of the fumarolic field of La Fossa crater (Vulcano Island, Aeolian Island), which we performed using a UV camera in two field campaigns: in November 12, 2009 and February 4, 2010. We derived~0.5 Hz SO 2 flux time-series finding fluxes from individual fumaroles, ranging from 2 to 8.7 t d −1 , with a total emission from the entire system of~20 t d −1 and~13 t d −1 , in November 2009 and February 2010 respectively. These data were augmented with molar H 2 S/SO 2 , CO 2 /SO 2 and H 2 O/SO 2 ratios, measured using a portable MultiGAS analyzer, for the individual fumaroles. Using the SO 2 flux data in tandem with the molar ratios, we calculated the flux of volcanic species from individual fumaroles, and the crater as a whole: CO 2 (684 t d −1 and 293 t d −1 ), H 2 S (8 t d −1 and 7.5 t d −1 ) and H 2 O (580 t d −1 and 225 t d −1 ).