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NASA NTRS1991

The evolution of volcanism, tectonics, and volatiles on Mars - An overview of recent progress

Significant results of the 'Mars: Evolution of Volcanism, Tectonics, and Volatiles' (MEVTV) project are presented. The data for the project are based on geological mapping from the Viking images, petrologic and chemical analyses of SNC meteorites, and both mapping and temporal grouping of major fault systems. The origin of the planet's crustal dichotomy is examined in detail, the kinematics and formation of wrinkle ridges are discussed, and some new theories are set forth. Because the SNC meteorites vary petrologically and isotopically, the sources of the parental Martian magma are heterogeneous. Transcurrent faulting coupled with the extensional strains that form Valles Marineris suggest early horizontal movement of lithospheric blocks. A theory which connects the formation of the crustal dichotomy to the Tharsis region associates the horizontal motions with plate tectonics that generated a new lithosphere.

Zimbelman, James R.↗

NASA NTRS1992

Was early Mars warmed by ammonia?

Runoff channels and valley networks present on ancient, heavily cratered Martian terrain suggests that the climate of Mars was originally warm and wet. One explanation for the formation of these channels is that the surface was warmed by the greenhouse effect of a dense, CO2 atmosphere. However, recent work shows that this theory is not consistent for the early period of the solar system. One way to increase the surface temperature predicted is to assume that other greenhouse gases were present in Mars' atmosphere in addition to CO2 and H2O. This possible gas is ammonia, NH3. If ammonia was present in sufficient quantities, it could have raised the surface temperature to 273 K. An adequate source would have been volcanic outgassing if the NH3 produced was shielded from photolysis by an ultraviolet light absorber.

Kasting, J. F.↗

NASA NTRS1994

Quantitative reflectance spectroscopy of buddingtonite from the Cuprite mining district, Nevada

Buddingtonite, an ammonium-bearing feldspar diagnostic of volcanic-hosted alteration, can be identified and, in some cases, quantitatively measured using short-wave infrared (SWIR) reflectance spectroscopy. In this study over 200 samples from Cuprite, Nevada, were evaluated by X ray diffraction, chemical analysis, scanning electron microscopy, and SWIR reflectance spectroscopy with the objective of developing a quantitative remote-sensing technique for rapid determination of the amount of ammonium or buddingtonite present, and its distribution across the site. Based upon the Hapke theory of radiative transfer from particulate surfaces, spectra from quantitative, physical mixtures were compared with computed mixture spectra. We hypothesized that the concentration of ammonium in each sample is related to the size and shape of the ammonium absorption bands and tested this hypothesis for samples of relatively pure buddingtonite. We found that the band depth of the 2.12-micron NH4 feature is linearly related to the NH4 concentration for the Cuprite buddingtonite, and that the relationship is approximately exponential for a larger range of NH4 concentrations. Associated minerals such as smectite and jarosite suppress the depth of the 2.12-micron NH4 absorption band. Quantitative reflectance spectroscopy is possible when the effects of these associated minerals are also considered.

Felzer, Benjamin↗

NASA NTRS1989

Tectonism on Venus: A review

Venus is more similar to Earth than to any other planet. It has elevated regions associated with marginal fold and thrust belts, fracture zones that extend tens of thousands of kilometers, crustal swells and shields that are hundreds of kilometers in diameter and 1 to 2 km high, and sublinear accumulations of volcanic cones and domes that stretch for thousands of kilometers across the plains. The Venusian surface is, however, distinctly different from Earth's in that: (1) its elevated terrains cannot be distinguished from its low plains on a hypsometric curve; (2) trenches have not been found plainsward of the marginal belts; (3) fracture zones bear no resemblance to mid-oceanic ridges; and (4) some features, such as the ridge-belt zone near 210 deg E, seem to have no terrestrial analog. Various theories about tectonism on Venus and Earth of other authors are reviewed.

Kozak, Richard C.↗

NASA NTRS1982

Microstructure and particulate properties of the surfaces of Io and Ganymede - Comparison with other solar system bodies

The phase curves of Io and Ganymede between 0 and 40 deg solar phase angle have been compiled from Voyager photopolarimeter and ground-based observations. Modeling the data with the Lumme-Bowell theory made it possible to determine improved estimates of the surface texture and particulate properties. Accurate V-band zero-phase geometric albedos, phase integrals, and Bond albedos are also obtained. The properties of the particles on Io's surface appear to be different from those of other solar system objects whose surfaces are totally controlled by impact cratering processes. Sulfur and SO2 frost, previously identified by spectral analysis, seem to exist in a physical form not commonly found on earth. The agglomeration of volcanic ash into aggregates on Io's surface is postulated.

Pang, K. D.↗

NASA NTRS1977

The relationship between crustal tectonics and internal evolution in the moon and Mercury

The relationship between crustal tectonics and thermal evolution is discussed in terms of the moon and Mercury. Finite strain theory and depth and temperature-dependent thermal expansion are used to evaluate previous conclusions about early lunar history. Factors bringing about core differentiation in the first 0.6 b.y. of Mercurian evolution are described. The influence of concentrating radioactive heat sources located in Mercury's crust on the predicted contraction is outlined. The predicted planetary volume change is explored with regard to quantitative limits on the extent of Mercurian core solidification. Lunar and Mercurian thermal stresses involved in thermal evolution are reviewed, noting the history of surface volcanism. It is concluded that surface faulting and volcanism are closely associated with the thermal evolution of the whole planetary volume. As the planet cools or is heated, several types of tectonic and volcanic effects may be produced by thermal stress occurring in the lithosphere.

Solomon, S. C.↗

NASA NTRS1994

An ethnographic object-oriented analysis of explorer presence in a volcanic terrain environment: Claims and evidence

An ethnographic field study was conducted to investigate the nature of presence in field geology, and to develop specifications for domain-based planetary exploration systems utilizing virtual presence. Two planetary geologists were accompanied on a multi-day geologic field trip that they had arranged for their own scientific purposes, which centered on an investigation of the extraordinary xenolith/nodule deposits in the Kaupulehu lava flow of Hualalai Volcano, on the island of Hawaii. The geologists were observed during the course of their field investigations and interviewed regarding their activities and ideas. Analysis of the interview resulted in the identification of key domain entities and their attributes, relations among the entities, and explorer interactions with the environment. The results support and extend the author's previously reported continuity theory of presence, indicating that presence in field geology is characterized by persistent engagement with objects associated by metonymic relations. The results also provide design specifications for virtual planetary exploration systems, including an integrating structure for disparate data integration. Finally, the results suggest that unobtrusive participant observation coupled with field interviews is an effective research methodology for engineering ethnography.

Mcgreevy, Michael W.↗

NASA NTRS1987

Revision of the Martian relative age chronology

This study has provided a more detailed chronology than currently exists in the literature and has created some changes to the currently accepted geological evolutionary sequence of Mars. The period of heavy bombardment, although dominated by impact processes, experienced many forms of volcanic activity and at least one episode of intense fracturing. Most small volcanic constructs and the ridged plains regions are found to date from this early period, contrary to common belief. The fracturing and dissection of the highlands helps to provide further constraints on the timing of events such as the formation of the hemispheric dichotomy and the formation of the Tharsis Bulge. The northern plains are found to consist of a number of differently aged regions. The difference in age between the chaotic terrain and the outflow channels together with differences in the distribution curves among craters of various erosional states found on the channels support the theory of episodic periods of flooding.

Barlow, Nadine G.↗

NASA NTRS1993

Impact and volcanism - A momentum scaling law for erosion

The controversy that raged through the 1950s to 1970s over similarities and differences between meteorite impact and volcanic processes is revisited. We propose that there are quantitative similarities in erosion caused by high-speed ejecta produced by either impacts or volcanic processes. Field and petrographic data from the Manicouagan impact crater, Canada, are used to demonstrate that, during the emplacement of the impact melt sheet, erosion occurred at a rate of 2562 kg/sq m per s. Field data for the Mount St. Helens lateral blast of May 18, 1980, suggest an erosion rate of 21 kg/sq m per s, and field data for a small pyroclastic flow on August 7, 1980, suggest an erosion rate of about 14 kg /sq m per s. It is proposed that these three rates were determined dominantly by the momentum of the ejecta, and a quantitative formulation based on lofting theory is given. A new application of the Monte Carlo approach to analysis provides minimum, most likely, and maximum estimates for both the field and the theoretical analyses. The substantial erosion that occurs by fast moving flows results in mixing of stratigraphic components over large distances and to very fine scales.

Simonds, Charles H.↗

NASA NTRS1999

A Study of Stratospheric Aerosols and Their Effect on Inorganic Chlorine Partitioning Using Balloon, In Situ, and Satellite Observations

Heterogeneous reactions on the surface of aerosols lead to a decrease in the concentration of nitrogen radicals and an increase in the concentration of chlorine and hydrogen radical species. As a consequence, enhanced sulfate aerosol levels in the lower stratosphere resulting from volcanic eruptions lead to lower concentrations of ozone due to more rapid loss by chlorine and hydrogen radicals. This study focuses on continuing the effort to quantify the effect of sulfate aerosols on the partitioning of inorganic chlorine species at midlatitudes. The study begins with an examination of balloon-borne measurements of key chlorine species obtained by the JPL MkIV interferometer for different aerosol loading conditions. A detailed comparison of the response of HCl to variations in aerosol surface area observed by MkIV, ER-2 instruments, HALOE, and ATMOS is carried out by examining HCl vs CH4 correlation diagrams, since CH4 is the only tracer measured on each platform. Finally, the consistency between theory and observed changes in ClO and HCl due to variations in aerosol surface area is examined.

Osterman, G. B.↗

NASA NTRS1993

Coherent launch-site atmospheric wind sounder - Theory and experiment

The coherent launch-site atmospheric wind sounder (CLAWS) is a lidar atmospheric wind sensor designed to measure the winds above space launch facilities to an altitude of 20 km. In our development studies, lidar sensor requirements are defined, a system to meet those requirements is defined and built, and the concept is evaluated, with recommendations for the most feasible and cost-effective lidar system for use as an input to a guidance and control system for missile or spacecraft launches. The ability of CLAWS to meet NASA goals for increased safety and launch/mission flexibility is evaluated in a field test program at Kennedy Space Center (KSC) in which we investigate maximum detection range, refractive turbulence, and aerosol backscattering efficiency. The Nd:YAG coherent lidar operating at 1.06 micron with 1-J energy per pulse is able to make real-time measurements of the 3D wind field at KSC to an altitude of 26 km, in good agreement with our performance simulations. It also shows the height and thickness of the volcanic layer caused by the volcanic eruption of Mount Pinatubo in the Philippines.

Hawley, James G.↗

NASA NTRS1985

Io: Generation of Silicate Magma by Shear Melting at the Base of a Basaltic Lithosphere

Tidal theory and observational evidence indicates that about 1 w/sq. m. of energy is released at the surface of Io. In order to place limits on how much tidal energy can be dissipated within a rigid lithosphere, depth-temperature profiles were calculated for different lithosphere thickness assuming that the tidal energy was dissipated uniformly throughout the lithosphere. Thus a thick lithosphere implies that a significant fraction of the tidal energy is dissipated below the depth where solidus temperatures are reached. One possibility is that Io has a crust consisting of a low melting temperature fraction such as basalt, overlying a mantle of a high melting temperature fraction such as peridotite. Thus, if the lithosphere of Io is thicker than 30 km, as appears probable, then high rates of silicate volcanism are implied and a significant fraction of the tidal energy must be dissipated by viscous deformation rather than rigid flexure.

Carr, M. H.↗

NASA NTRS1993

Mantle redox evolution and the oxidation state of the Archean atmosphere

Current models predict that the early atmosphere consisted mostly of CO2, N2, and H2O, along with traces of H2 and CO. Such models are based on the assumption that the redox state of the upper mantle has not changed, so that volcanic gas composition has remained approximately constant with time. We argue here that this assumption is probably incorrect: the upper mantle was originally more reduced than today, although not as reduced as the metal arrest level, and has become progressively more oxidized as a consequence of the release of reduced volcanic gases and the subduction of hydrated, oxidized seafloor. Data on the redox state of sulfide and chromite inclusions in diamonds imply that the process of mantle oxidation was slow, so that reduced conditions could have prevailed for as much as half of the earth's history. To be sure, other oxybarometers of ancient rocks give different results, so the question of when the mantle redox state has changed remains unresolved. Mantle redox evolution is intimately linked to the oxidation state of the primitive atmosphere: A reduced Archean atmosphere would have had a high hydrogen escape rate and should correspond to a changing mantle redox state; an oxidized Archean atmosphere should be associated with a constant mantle redox state. The converses of these statements are also true. Finally, our theory of mantle redox evolution may explain why the Archean atmosphere remained oxygen-deficient until approximately 2.0 billion years ago (Ga) despite a probable early origin for photosynthesis.

NASA Discipline Number 52-30↗

NASA NTRS1988

The Western North American Cretaceous-Tertiary (K-T) boundary interval and its content of shock-metamorphosed minerals: Implications concerning the K-T boundary impact-extinction theory

At 20 sites in the Raton Basin of Colorado and New Mexico, and at several other sites in Wyoming, Montana, and Canada, a pair of claystone units, an Ir abundance anomaly, and a concentration of shock-metamorphosed minerals mark the palynological K-T boundary. The K-T boundary claystone, which is composed of kaolinite and small amounts of illite/smectite mixed-layer clay, is similar in most respects to kaolinite tonstein layers in coal beds. At some, but not all, K-T boundary localities, the boundary claystone contains solid kaolinite and hollow and solid goyazite spherules, 0.05 to 1.2 mm in diameter. The upper unit, the K-T boundary impact layer, consists chiefly of kaolinite and various amounts of illite/smectite mixed-layer clay. The impact layer and boundary claystone are similar chemically, except that the former has slightly more Fe, K, Ba, Cr, Cu, Li, V, and Zn than the latter. The facts that the boundary claystone and impact layer contain anomalous amounts of Ir, comprise a stratigraphic couplet at Western North American sites, and form thin, discrete layers, similar to air-fall units (volcanic or impact), suggest that the claystone units are of impact origin. Significantly, the impact layer contains as much as 2 percent clastic mineral grains, about 30 percent of which contain multiple sets of shock lamellae. Only one such concentration of shocked minerals has been found near the K-T boundary. The type of K-T boundary shock-metamorphosed materials (quartzite and metaquartzite) in the impact layer and the lack of shock lamellae in quartz and feldspar of pumice lapilli and granitic xenoliths in air-fall pumice units of silicic tuffs, such as the Bishop Tuff, eliminate the possibility that the shock-metamorphosed minerals in the K-T impact layer are of volcanic origin. The global size distribution and abundance of shock-metamorphosed mineral grains suggest that the K-T impact occurred in North America.

Izett, G. A.↗

NASA NTRS1993

A discussion of plausible solar irradiance variations, 1700-1992

From satellite observations the solar total irradiance is known to vary. Sunspot blocking, facular emission, and network emission are three identified causes for the variations. In this paper we examine several different solar indices measured over the past century that are potential proxy measures for the Sun's irradiance. These indices are (1) the equatorial solar rotation rate, (2) the sunspot structure, the decay rate of individual sunspots, and the number of sunspots without umbrae, and (3) the length and decay rate of the sunspot cycle. Each index can be used to develop a model for the Sun's total irradiance as seen at the Earth. Three solar indices allow the irradiance to be modeled back to the mid-1700s. The indices are (1) the length of the solar cycle, (2) the normalized decay rate of the solar cycle, and (3) the mean level of solar activity. All the indices are well correlated, and one possible explanation for their nearly simultaneous variations is changes in the Sun's convective energy transport. Although changes in the Sun's convective energy transport are outside the realm of normal stellar structure theory (e.g., mixing length theory), one can imagine variations arising from even the simplest view of sunspots as vertical tubes of magnetic flux, which would serve as rigid pillas affecting the energy flow patterns by ensuring larger-scale eddies. A composite solar irradiance model, based upon these proxies, is compared to the northern hemisphere temperature depatures for 1700-1992. Approximately 71% of the decadal variance in the last century can be modeled with these solar indices, although this analysis does not include anthropogenic or other variations which would affect the results. Over the entire three centuries, approx. 50% of the variance is modeled. Both this analysis and previous similar analyses have correlations of model solar irradiances and measured Earth surface temperatures that are significant at better than the 95% confidence level. To understand our present climate variations, we must place the anthropogenic variations in the context of natural variability from solar, volcanic, oceanic, and other sources.

Hoyt, Douglas V.↗

NASA NTRS2022

Diffusion in Melts and Magmas

Diffusion results from random motion of particles and entities. Diffusion in melts and magmas is due to thermally excited random motion of atoms, ions, and clusters, and plays a critical role in magmatic and volcanic processes. In melts and magmas, diffusion is one of the two mechanisms of mass transfer; the other being bulk flow (referred to as convection or advection). When both are present, diffusion refers to the dispersive motion relative to the mean bulk flow in a given reference frame (Richter et al. 1998). Diffusion plays critical roles in controlling magma mixing (Watson 1982; Koyaguchi 1985, 1989; Lesher 1994; Huber et al. 2009; Guo and Zhang 2020), mineral growth and dissolution rates in magmas (e.g., Watson 1982; Harrison and Watson 1983; Zhang et al. 1989; Newcombe et al. 2014; Macris et al. 2018), bubble growth and dissolution rate in magmas (Sparks 1978; Proussevitch and Sahagian 1998; Liu and Zhang 2000; Zhang 2013), and elemental and isotope fractionation during mineral 2 growth and dissolution (Jambon 1980; Richter et al. 1999, 2003; Watson and Muller 2009; Chopra et al. 2012; Watkins et al. 2014, 2017; Holycross et al. 2016, 2018). As a result, diffusion also plays an essential role in explosive volcanic eruptions and magma crystallization. Furthermore, diffusion has important applications in geospeedometry (Lasaga 1983, 1998; Zhang 1994, 2008; Trail et al. 2016; Zhang and Xu 2016). Experimental investigation of diffusion in geologically relevant silicate melts began to flourish in the 1970’s when micro-analytical measurements of diffusion profiles became available. In addition to the vast number of papers published since then, numerous books and reviews are available for diffusion in silicate melts. Hofmann et al. (1974) edited a book titled “Geochemical Transport and Kinetics” published by Carnegie Institution of Washington. This was the first landmark book summarizing the field. Lasaga and Kirkpatrick (1981) edited a book “Kinetics of Geochemical Processes” as volume 8 of the Reviews in Mineralogy (later becoming Reviews in Mineralogy and Geochemistry) series. Zhang and Cherniak (2010) edited “Diffusion in Minerals and Melts” as volume 72 of Reviews of Mineralogy and Geochemistry series, in which one chapter focused on diffusion theory, five chapters on diffusion in silicate melts (Behrens 2010; Lesher 2010; Liang 2010; Zhang and Ni 2010; Zhang et al. 2010), and other chapters were on experimental, analytical, and computational methods, and diffusion in minerals. Several textbooks covered the principles and applications of diffusion theories (Kirkaldy and Young 1987; Shewmon 1989; Cussler 1997; Lasaga 1998; Zhang 2008; Vrentas and Vrentas 2016), and two classic books covered the mathematics of diffusion (Carslaw and Jaeger 1959; Crank 1975). In preparing for this review chapter, we thought carefully about what to cover for this vast field, and decided to briefly go through the fundamentals of diffusion (more complete review can be found in Chakraborty 1995; Zhang 2008, 2010) and solutions to often-encountered 3 diffusion problems, and then focus on post-2010 diffusion studies on silicate melts and magmas. Here, melts refer to (mostly natural) silicate liquid, and magmas refer to crystal-bearing and/or bubble-bearing melts in which the continuous phase is the melt. There is a large body of work on diffusion in glasses, especially in the materials science literature, which is not covered in this review.

Youxue Zhang↗

NASA NTRS2014

Geology Before Pluto: Pre-Encounter Considerations

Pluto, its large satellite Charon, and its four known satellites represent the first trans-Neptunian Kuiper Belt objects populating the outer-most solar system beyond the gas giant planets to be studied in detail from a spacecraft (New Horizons). A complete picture of the solar nebula, and solar system formation cannot be confidently formulated until representatives of this group of bodies at the edge of solar space have been examined. The Pluto system is composed of unique lunar- and intermediate-sized objects that can tell us much about how objects with volatile icy compositions evolve. Modeling of the interior suggests that geologic activity may have been to some degree, and observations of frost on the surface could imply the need for a geologic reservoir for the replenishment of these phases. However, the putative indicators of Pluto's geologic history are inconclusive and unspecific. Detailed examination of Pluto's geologic record is the only plausible means of bridging the gap between theory and observations. In this talk I will examine the potential importance of these tentative indications of geologic activity and how specific spacecraft observations have been designed and used to constrain the Pluto system's geologic history. The cameras of New Horizons will provide robust data sets that should be immanently amenable to geological analysis of the Pluto System's landscapes. In this talk, we begin with a brief discussion of the planned observations by New Horizons' cameras that will bear most directly on geological interpretability. Then I will broadly review major geological processes that could potentially operate of the surfaces of Pluto and its moons. I will first survey exogenic processes (i.e., those for which energy for surface modification is supplied externally to the planetary surface): impact cratering, sedimentary processes (including volatile migration) and the work of wind. I will conclude with an assessment of prospects for endogenic activity in the form of tectonics and cryo-volcanism.

Pluto↗

NASA NTRS2010

Direct Retrieval of Sulfur Dioxide Amount and Altitude from Spaceborne Hyperspectral UV Measurements: Theory and Application

We describe the physical processes by which a vertically localized absorber perturbs the top-of-atmosphere solar backscattered ultraviolet (UV) radiance. The distinct spectral responses to perturbations of an absorber in its column amount and layer altitude provide the basis for a practical satellite retrieval technique, the Extended Iterative Spectral Fitting (EISF) algorithm, for the simultaneous retrieval of these quantities of a SO2 plume. In addition, the EISF retrieval provides an improved UV aerosol index for quantifying the spectral contrast of apparent scene reflectance at the bottom of atmosphere bounded by the surface and/or cloud; hence it can be used for detection of the presence or absence of UV absorbing aerosols. We study the performance and characterize the uncertainties of the EISF algorithm using synthetic backscattered UV radiances, retrievals from which can be compared with those used in the simulation. Our findings indicate that the presence of aerosols (both absorbing and nonabsorbing) does not cause large errors in EISF retrievals under most observing conditions when they are located below the SO2 plume. The EISF retrievals assuming a homogeneous field of view can provide accurate column amounts for inhomogeneous scenes, but they always underestimate the plume altitudes. The EISF algorithm reduces systematic errors present in existing linear retrieval algorithms that use prescribed SO2 plume heights. Applying the EISF algorithm to Ozone Monitoring Instrument satellite observations of the recent Kasatochi volcanic eruption, we demonstrate the successful retrieval of effective plume altitude of volcanic SO2, and we also show the improvement in accuracy in the corresponding SO2 columns.

Yang, Kau↗