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One of the strengths of laser-induced breakdown spectroscopy (LIBS) is that a large amount of data can be measured relatively easily in a short time, which makes LIBS interesting in many areas, from geomaterial analysis with portable handheld instruments to applications for the exploration of planetary surfaces. Statistical methods, therefore, play an important role in analyzing the data to detect not only individual compositions but also trends and correlations. In this study, we apply two approaches to explore the LIBS data of geomaterials measured with a handheld device at different locations on the Aeolian island of Vulcano, Italy. First, we use the established method, principal component analysis (PCA), and second we adopt the principle of the interesting features finder (IFF), which was recently proposed for the analysis of LIBS imaging data. With this method it is possible to identify spectra that contain emission lines of minor and trace elements that often remain undetected with variance-based methods, such as PCA. We could not detect any spectra with IFF that were not detected with PCA when applying both methods to our LIBS field data. The reason for this may be the nature of our field data, which are subject to more experimental changes than data measured in laboratory settings, such as LIBS imaging data, for which the IFF was introduced first. In conclusion, however, we found that the two approaches complement each other well, making the exploration of the data more intuitive, straightforward, and efficient. [ABSTRACT FROM AUTHOR]

Context. The magma ocean period was a critical phase determining how Earth's atmosphere developed into habitability. However, there are major uncertainties in the role of key processes such as outgassing from the planetary interior and escape of species to space that play a major role in determining the atmosphere of early Earth. Aims. We investigate the effect of outgassing of various species and escape of H2 for different mantle redox states upon the composition and evolution of the atmosphere for the magma ocean period. Methods. We included an important new atmosphere-interior coupling mechanism: the redox evolution of the mantle, which strongly affects the outgassing of species. We simulated the volatile outgassing and chemical speciation at the surface for various redox states of the mantle by employing a C-H-O based chemical speciation model combined with an interior outgassing model. We then applied a line-by-line radiative transfer model to study the remote appearance of the planet in terms of the infrared emission and transmission. Finally, we used a parameterized diffusion-limited and XUV energy-driven atmospheric escape model to calculate the loss of H2 to space. Results. We have simulated the thermal emission and transmission spectra for reduced and oxidized atmospheres present during the magma ocean period of Earth. Reduced/thin atmospheres consisting of H2 in abundance emit more radiation to space and have a larger effective height than oxidized/thick atmospheres, which are abundant in H2O and CO2. We obtain that the outgassing rates of H2 from the mantle into the atmosphere are a factor of ten times higher than the rates of diffusion-limited escape to space. We estimate the timescale of total mass loss of outgassed H2 via escape to be few tens of million years, which is comparable to other studies. Conclusions. Our work presents useful insight into the development of the terrestrial atmosphere during the magma ocean period and provides input to guide future studies that discuss exoplanetary interior compositions and their possible links with atmospheric compositions that might be estimated from observed infrared spectra by future missions. [ABSTRACT FROM AUTHOR]

The early history of the Earth was characterized by a magma ocean stage. The principal aimof this research is a better investigation of the magma ocean interior-surface-atmosphereinteractions by combining several modelling approaches. We analyse the degassing rateduring the early phase of the magma ocean and the related chemical speciation of theoutgassed volatile phases. Moreover, by simulating the structure of the atmosphere wecalculate the cooling rate at its top, and therefore of the whole planet. The degassing rate is provided by a 1D interior-atmosphere coupled model that resolvesthe magma ocean solidification and its thermal evolution. The two volatile species H2O andCO2 included are dissolved in the melt and they are degassed when their solubility in themelt is exceeded. Progressive solidification of the mantle ensures an increase in thecumulative atmospheric mass. Moreover, the volatile chemical speciation of the C-O-Hsystem is analysed with the equilibrium and mass balance method. Since the gaschemical composition is affected by the volatile availability of the magma oceanand by the melt oxygen fugacity, this method shows the direct link between theinterior and the development of the atmosphere. We observed that under reducedcondition (QIF and IW mineral buffers) the dominant outgassed gas phases are H2and CO. On the other hand, with an oxidizing ambient (NiNiO and QIF mineralbuffers) the principal gas phases are H2O and CO2. Furthermore, the structure and theevolution of the atmosphere are investigated. We calculate the outgoing longwaveradiation at the top of the atmosphere using the line-by-line radiative transfer codeGARLIC. The results of the present research show that an interdisciplinary approach is a key pointto shed light on the interior-surface-atmosphere interactions and on the early Earth evolution.The transition of the volatiles from the interior to the surface was affected both by the thermaland redox evolution of the mantle. These interactions influenced the composition of theearly atmosphere and the related cooling rate of the planet. Lastly, considering anextension of the present scope, this analytical technique has the potential also tocharacterise the volatile behaviour and the thermal evolution of solid exoplanets. [ABSTRACT FROM AUTHOR]

We present new evidence that shows magma mingling can be a key process during highly explosive eruptions. Using fractal analysis of the size distribution of trachybasaltic fragments found on the inner walls of bubbles in trachytic pumices, we show that the more mafic component underwent fracturing during quenching against the trachyte. We propose a new mechanism for how this magmatic interaction at depth triggered rapid heterogeneous bubble nucleation and growth and could have enhanced eruption explosivity. We argue that the data support a further, and hitherto unreported contribution of magma mingling to highly explosive eruptions. This has implications for hazard assessment for those volcanoes in which evidence of magma mingling exists.