Preface: Workshop on matter,astrophysics, gravitation,ions and cosmology—MAGIC23

We outline our experience in organizing the first edition of the Workshop on Matter, Astrophysics, Gravitation, Ions and Cosmology, held in virtual and in-person format, denominated MAGIC23, held from 6 to 10 March, 2023, in Praia do Rosa, Santa Catarina, Brazil. The event aimed to bring together leading academic scientists, professors, students, and research scholars for exchanging experiences and discuss the most recent innovations, trends, practical challenges, and experimental and theoretical solutions adopted in the investigation fields within the scope of the meeting. The workshop offered to the participants a platform for scientific and academic projects, partnerships, and presentation of high-quality research contributions describing original and unpublished results on topics related to matter, astrophysics, gravitation, ions, and cosmology.     

Analysis of Manning coefficient for small‐depth flows on vegetated beds

The limitations of Manning's formula are analysed when it is in extreme conditions, and more specifically with small‐depth flows on natural‐vegetation beds. A thorough analysis is made of research carried out on macro‐rough beds, placing particular emphasis on vegetated beds. Research carried out to date on the roughness of vegetated beds and macro‐roughness is commented on, including that carried out at the Laboratory of Hydraulics and Hydrology of the Forestry Engineering Faculty (Polytechnic University of Madrid). The work was done in two phases, the first in a laboratory channel with artificial vegetation and the second in natural beds. The results of the experimental research allow the development of a new approximate method of determining Manning coefficient according to the Froude number. This method may be applied in extreme conditions, both in small depths and steep slopes. It was proved that the Manning coefficient depends not only on roughness height, but also on depth and slope values; thus, it is advisable to choose the appropriate method for its calculation. Copyright © 2005 John Wiley & Sons, Ltd.     

Moments of the lunar disturbing force

Summary The components of the moments of the external force due to the gravitational effect of the Moon are derived, which causes disturbances in the motion of the Earth round its mass centre, taking into account the gravitational fields of both bodies in the form of a development in terms of harmonics upto degree n=4. This paper ties up with [3–5] and the notations are identical.     

Geodetic and geophysical implications of the homogeneous reduction of pole coordinates (1899–1979)

The new series ILS (H) of pole coordinates (1899.9–1979.0) computed in a homogeneous system has been employed for the determination of the period of Chandler's component of polar motion. The comparison with a value derived from a previous series ILS (VY) shows there is no significant variation in the period in spite of the known systematic errors affecting the ILS (VY) series. Any high precision geodetic network adjustment has to take account of the pole coordinates defined by the ILS (H) series. Such long series permitted the identification of another component of polar motion with a period of about 30 years. The polhode derived from the ILS (H) series shows greater regularity than previously deduced polhodes and, therefore, we can conclude that past investigations in geodesy and geophysics trying to correlated the irregularities of the polhode with different geophysical phenomena, for instance, earthquakes, may have to be revised.     

A stress and displacement discontinuity element method for elastic transversely anisotropic rock

The paper presents closed‐form solutions for stress and displacement influence functions for stress discontinuity (SD) and displacement discontinuity (DD) elements, for a two‐dimensional plane‐strain elastic, transversely anisotropic medium. The solutions for SD elements are based on Kelvin's problem and for DD elements on the concept of dipoles. Stress and displacement influence functions are derived for the following elements: constant SD, linear SD, constant DD, linear DD, square root DD, parabolic DD, constant DD surface, and linear DD surface elements. The formulations are incorporated into FROCK, a hybridized boundary element method code, and are validated by providing comparisons between the results from FROCK and the finite element code ABAQUS. A limited parametric analysis shows the effects of slight anisotropy on the stress field around the tip of a crack and of the orientation of the crack with respect to the axes of elastic symmetry. Copyright © 2014 John Wiley & Sons, Ltd.     

Significance of ancient sulfide PGE and Re–Os signatures in the mantle beneath Calatrava,Central Spain

Spinel lherzolite and wehrlite xenoliths from the Cenozoic Calatrava volcanic field carry the geochemical imprint of metasomatic agents that have affected the subcontinental lithospheric mantle beneath Central Iberia. Some xenoliths (mainly wehrlites) were enriched in REE, Sr, P, and CO₂ by silicic-carbonate-rich metasomatic melts/fluids, while others record the effects of subduction-related hydrous silicate fluids that have precipitated amphibole and induced high Ti/Eu in primary clinopyroxene. The petrographic observations and geochemical data suggest that interstitial glass in the xenoliths represent the quenched products of Si-rich melts that infiltrated the mantle peridotite shortly before the entrainment of the xenoliths in the host magmas that erupted ca 2 million years ago. During their infiltration, the metasomatic melts reacted with peridotite, resulting in silica enrichment, while remobilizing grains of iron-rich monosulfide solid solution (Fe-rich Mss) initially enclosed in, or intergranular to, primary olivine and pyroxenes. In situ laser ablation inductively coupled plasma-mass spectrometry analysis of single sulfide grains reveals that the Fe-rich Mss in glass shows platinum-group element (PGE) patterns and ¹⁸⁷Os/¹⁸⁸Os compositions identical to the Fe-rich Mss occurring as inclusions in, or at grain boundaries of primary silicates. Moreover, independent of its microstructural position, Fe-rich Mss exhibits PGE and ¹⁸⁷Os/¹⁸⁸Os signatures typical of Mss either residual after partial melting or crystallized directly from sulfide melts. Our findings reveal that young metasomatic melt(s)/fluid(s) may carry remobilized sulfides with PGE and Os-isotopic signatures identical to those of texturally older sulfides in the peridotite xenolith. These sulfides thus still provide useful information about the timing and nature of older magmatic events in the subcontinental mantle.     

GIS application for regional assessment of seismically induced slope failures in the Sierra Nevada Range,South Spain,along the Padul Fault

Complete rupture of the Padul Fault represents one of the largest plausible earthquakes in the Sierra Nevada Range, one of the most seismically active regions of Spain. We performed a regional assessment of earthquake-triggered slope instabilities in the western part of the range to determine the most likely types of failures from such an earthquake in the region and suggest where such failures have a higher likelihood of occurring. These results are broadly useful for management of regional life-lines and future development. First, a slope-instability inventory of the Sierra Nevada was produced to identify the most common instability types. Subsequently, the Newmark’s sliding rigid-block methodology, implemented in a geographic information system, was used to obtain the distribution of Newmark displacements in the area considering a M _w 6.6 earthquake on the Padul Fault. The Newmark displacements were then compared to the distribution of the inventoried slope instabilities to identify the areas where seismicity could reactivate old slope instabilities or generate new ones, and to identify the involved landslide typology. The most likely seismically induced slope instabilities in the Sierra Nevada are rock falls and rock slides. These types of instabilities could be triggered by Newmark displacements of 2 cm or less.     

Mercury colonial footprint in Darién Gulf sediments,Colombia

The mercury (Hg) deposition history in the Darién Gulf is reconstructed from three sediment cores spanning up to 1,000 years. Knowledge on the contribution to global Hg budget from the Caribbean is limited. Patterns of water circulation, sediment deposition rates, cataclysmic atmospheric inputs, and post-depositional migration have been considered in Hg trapping in the seabed. The sediment delivery rates to the coastal zone over the Late Holocene have increased from 0.2 to 1 cm year^?1 owing to anthropogenic influence. This alteration took the form of geological effects, like coastal morphology change, that played a major role in Hg downcore signal preservation. Natural background Hg levels in Southern Caribbean sediments (77.0 μg kg^?1) are up to three times higher than preindustrial signals at other latitudes, because of volcanic contributions from the Pacific ring of fire. Enrichment factors rose from 0.9 to 1.5 (70.1–113.5 μg kg^?1) within profiles related to Hg usage since Spanish colonial times between the calendar years 1550 and 1811.     

The origin of the high-K latites from Camp Creek,Arizona: constraints from experiments with variable fO2 and a_{{\text{H}}_{\text{2}} {\text{O}}}

Near-liquidus melting experiments were performed on a high-K latite at fO₂'s ranging from iron-wustite-graphite (IWG) to nickel-nickel oxide (NNO) in the presence of a C-O-H fluid phase. Clinopyroxene is a liquidus phase under all conditions. At IWG , the liquidus at 10 kb is about 1,150° C but is depressed to 1,025° C at NNO and . Phlogopite and apatite are near-liquidus phases, with apatite crystallizing first at pressures below 10 kb. Phlogopite is a liquidus phase only at NNO and high . Under all conditions the high-K latites show a large crystallization interval with phlogopite becoming the dominant crystalline phase with decreasing temperature. Increasing fO₂ affects phlogopite crystallization but the liquidus temperature is essentially a function of . The chemical compositions of the near-liquidus phases support formation of the high-K latites under oxidizing conditions (NNO or higher) and high . It is concluded from the temperature of the H₂O-saturated liquidus at 10 kb, the groundmass: crystal ratio and presence of chilled latite margins around some xenoliths that the Camp Creek high-K latite magma passed thru the lower crust at temperatures of 1,000° C or more.