Single-station inversion of seismic data for the InSight mission to Mars

Terrestrial planets, such as Earth and Mars, possess a crust that forms during the accretion phase, preserving impressions of the fundamental processes involved in their formation and evolution. Unlike Earth, where most of the ancient crust has been recycled, Mars retains most of it as it does not possess plate tectonics. Investigation of its crustal thickness and structure can thus help constrain its early evolution and formation. In November 2018, NASA’s InSight mission successfully deployed a three-component, very broad-band seismometer on the surface of Mars. With continuous seismic monitoring of Mars for over three Earth years, the seismic data from InSight now presents us with an opportunity for in-situ investigation of the Martian crust for the very first time. This thesis presents the development and application of a single-station seismic method to image the crust of Mars and evaluate its crustal thickness and structure below the InSight landing site using recorded marsquakes

Implications of New Quantum Spin Perspective In Quantum Gravity

Consequences of new quantum spin perspective in quantum gravity are far-reaching. Results of this novel perspective in loop quantum gravity, i.e., the modification of the equation of geometrical operators such as the area and the volume operator are known. Using newly proposed formula from this perspective, the magnitude of fundamental constants such as the reduced Planck constant $\hbar$, the gravitational constant $G$, the speed of light $c$, the Boltzmann constant $k_{\beta}$, the fine structure constant $\alpha$, can be validated. With the aid of this perspective, we find new formulas for the fundamental Planckian quantities and the derived Planckian quantities. We also propose novel formulas for the Planck star such as the size, the curvature, the surface area and the size of black hole (for the Planck star) without modifying its significance. The relation of the quantum spin with the Planck temperature $T_{P}$ $(T_{p} \propto n^{2})$, the Planck mass $m_{P}$ $(m_{P} \propto n^{2})$, the Planck length $l_{P}$ $(l_{P} \propto n)$ are also proposed using this novel perspectiveComment: 13 page

Constraints for the Martian Crustal Structure From Rayleigh Waves Ellipticity of Large Seismic Events

For the first time, we measured the ellipticity of direct Rayleigh waves at intermediate periods (15-35 s) on Mars using the recordings of three large seismic Martian events, including S1222a, the largest event recorded by the InSight mission. These measurements, together with P-to-s receiver functions and P-wave reflection times, were utilized for performing a joint inversion of the local crustal structure at the InSight landing site. Our inversion results are compatible with previously reported intra-crustal discontinuities around 10 and 20 km depths, whereas the preferred models show a strong discontinuity at ~37 km, which is interpreted as the crust-mantle interface. Additionally, we support the presence of a shallow low-velocity layer of 2-3 km thickness. Compared to nearby regions, lower seismic wave velocities are derived for the crust, suggesting a higher porosity or alteration of the whole local crust

The interior of Mars as seen by InSight (Invited)

InSight is the first planetary mission dedicated to exploring the whole interior of a planet using geophysical methods, specifically seismology and geodesy. To this end, we observed seismic waves of distant marsquakes and inverted for interior models using differential travel times of phases reflected at the surface (PP, SS...) or the core mantle-boundary (ScS), as well as those converted at crustal interfaces. Compared to previous orbital observations1-3, the seismic data added decisive new insights with consequences for the formation of Mars: The global average crustal thickness of 24-75 km is at the low end of pre-mission estimates5. Together with the the thick lithosphere of 450-600 km5, this requires an enrichment of heat-producing elements in the crust by a factor of 13-20, compared to the primitive mantle. The iron-rich liquid core is 1790-1870 km in radius6, which rules out the existence of an insulating bridgmanite-dominated lower mantle on Mars. The large, and therefore low-density core needs a high amount of light elements. Given the geochemical boundary conditions, Sulfur alone cannot explain the estimated density of ~6 g/cm3 and volatile elements, such as oxygen, carbon or hydrogen are needed in significant amounts. This observation is difficult to reconcile with classical models of late formation from the same material as Earth. We also give an overview of open questions after three years of InSight operation on the surface of Mars, such as the potential existence of an inner core or compositional layers above the CM

Detection, analysis, and removal of glitches from InSight's seismic data from Mars

The instrument package SEIS (Seismic Experiment for Internal Structure) with the three very broadband and three short‐period seismic sensors is installed on the surface on Mars as part of NASA's InSight Discovery mission. When compared to terrestrial installations, SEIS is deployed in a very harsh wind and temperature environment that leads to inevitable degradation of the quality of the recorded data. One ubiquitous artifact in the raw data is an abundance of transient one‐sided pulses often accompanied by high‐frequency spikes. These pulses, which we term “glitches”, can be modeled as the response of the instrument to a step in acceleration, while the spikes can be modeled as the response to a simultaneous step in displacement. We attribute the glitches primarily to SEIS‐internal stress relaxations caused by the large temperature variations to which the instrument is exposed during a Martian day. Only a small fraction of glitches correspond to a motion of the SEIS package as a whole caused by minuscule tilts of either the instrument or the ground. In this study, we focus on the analysis of the glitch+spike phenomenon and present how these signals can be automatically detected and removed from SEIS's raw data. As glitches affect many standard seismological analysis methods such as receiver functions, spectral decomposition and source inversions, we anticipate that studies of the Martian seismicity as well as studies of Mars' internal structure should benefit from deglitched seismic data.Centre National d'Etudes Spatiales (CNES)Swiss SpaceOffice (SSO)Agence Nationale de la RechercheDLR German Space AgencyInSight PSP progra

New Quantum Spin Perspective of Quantum Gravity and Space-Time of Mind-Stuff

The fundamental building block of the loop quantum gravity (LQG) is the spin network which is used to quantize the physical space-time in the LQG. Recently, the novel quantum spin is proposed using the basic concepts of the spin network. This perspective redefines the notion of the quantum spin and also introduces the novel definition of the reduced Planck constant. The implication of this perspective is not only limited to the quantum gravity; but also found in the quantum mechanics. Using this perspective, we also propose the quantization of the mind-stuff. Similarity between the physical space-time and the space-time of the mind-stuff provides novel notions to study the space-time scientifically as well philosophically. The comparison between the physical- space-time and the space-time of the mind-stuff is also studied

Influence of water soluble polyacrylamide on cyclohexane / CTAB / 1-propanol/water system

26-33<span style="font-size:12.0pt;font-family: " times="" new="" roman";mso-fareast-font-family:"times="" roman";mso-ansi-language:="" en-in;mso-fareast-language:en-in;mso-bidi-language:ar-sa"="" lang="EN-IN">The pseudoternary phase diagram of the system cyclohexane/CTAB/1-propanol/water has been constructed at different temperatures from 30° to 60°C. The mass ratio between CTAB and 1-propanol has been kept at 1:2. The phase diagrams have also been constructed in presence of polyacrylamide (PAA). Both the temperature and concentration of PAA have been varied; it is found that in presence of 0.005% PAA, the monophasic region is somewhat favoured. However, at higher concentrations of PAA, the monophasic region decreases drastically. The physicochemical properties have also been studied at different concentrations of PAA. The percolation is not observed in presence or in absence of 0.005% PAA. Optimal salinity values seem to be independent of temperature and are found to be controlled by individual ions of the electrolyte rather than the electrolyte. The adiabatic compressibility of the microemulsions (μE) is found to decrease with increase in the volume fraction of water.</span

New Quantum Spin Perspective and Geometrical Operators of Quantum Geometry

In this paper, we propose a new perspective of quantum spin (angular momentum) in which the Boltzmann constant $k_{\beta}$, Planck temperature $T_{P}$, Planck mass $m_{P}$ and Planck area $l_{P}^{2}$ are the integral part of the total angular momentum $J$. With the aid of this new perspective, we modify the equation of the area and volume operator. In the quantum geometry, for $SO(3)$ group, the angular momentum operators $J^{k}$ is the $k$th Lie group generator $t^{k}$; hence, $t^{k} \equiv J^{k}$. Therefore, new perspective of quantum spin can be directly applicable to quantum geometry. From data, the value of the area operator $\hat{A}_{S}$ increases with $n^{2}$ in discrete way that suggests discrete spectrum of the area operator similar to the actual formula of the area operator. This perspective provides an \textit{auto-correct} or \textit{auto-balance} mechanism within the equation of these geometrical operators. At the quantum gravity scale, it means that the mutual small change in $T_{P}$, $m_{P}$, and $l_{P}^{2}$ occur in such a way that $\hbar$, $l_{P}$ and $\hat{A}_{S}$ and $\hat{V}_{S}$ remain invariant for a value of $j_{i}$. The constancy of the reduced Planck constant $\hbar$ in the geometrical operators can provide a way through which smooth transition of the Planck scale to the nuclear or the atomic scale can be understood.Comment: 5 pages, 1 figure, 1 tabl

Physicochemical studies of cyclohexane/CTAB/l-propanol/water microemulsion system in the presence of PEG 400

38-45The phase behaviour and properties of a microemulsion system cyclohexane/CTAB/l-propanoV water have been studied at various temperatures between 300 and 80°C both in the presence and absence of PEG 400, PEG 400 does not have much effect on the properties of this microemulsion system. The conductance does not show percolation and a bicontinuous structure of the single phase microemulsion is envisaged. Viscosity of the PEG 400 containing system is higher than those without PEG. Optimal salinity values have been found to be independent of temperature and the values are determined by the individual ions rather than the electrolyte itself

The Barbero–Immirzi Parameter: An Enigmatic Parameter of Loop Quantum Gravity

The Barbero–Immirzi parameter, (γ), is introduced in loop quantum gravity (LQG), whose physical significance is still the biggest open question because of its profound traits. In some cases, it is real valued, while it is complex valued in other cases. This parameter emerges in the process of denoting a Lorentz connection with a non-compact group SO(3,1) in the form of a complex connection with values in a compact group of rotations, either SO(3) or SU(2). Initially, it appeared in the Ashtekar variables. Fernando Barbero proposed its possibility for inclusion within formalism. Its present value is fixed by counting micro states in loop quantum gravity and matching with the semi-classical black hole entropy computed by Stephen Hawking. This parameter is used to count the size of the quantum of area in Planck units. Until the discovery of the spectrum of the area operator in LQG, its significance remained unknown. However, its complete physical significance is yet to be explored. In the present paper, an introduction to the Barbero–Immirzi parameter in LQG, a timeline of this research area, and various proposals regarding its physical significance are given