Definition of earth science: any of the sciences (such as geology, meteorology, or oceanography) that deal with the earth or with one or more of its parts [https://www.merriam-webster.com/dictionary/earth%20science#h1, on 03.06,2029, at 11:31 AM].
Earth Science is the study of the Earth and its neighbors in space. The four basic areas of Earth science study are: geology, meteorology, oceanography, and astronomy, each of which is further broken down into more specialized fields. The word Geology means “study of the Earth.” It deals with the composition of Earth materials, Earth structures, and Earth processes. Meteorology is the study of the atmosphere and how processes in the atmosphere determine Earth's weather and climate. Oceanography is the study of Earth's oceans — their composition, movement, organisms and processes. Astronomy is the study of the universe [https://geology.com/articles/what-is-earth-science.shtml, on 03.06,2029, at 11:31 AM]. Also included by some are the cryosphere (corresponding to ice) as a distinct portion of the hydrosphere and the pedosphere (corresponding to soil) as an active and intermixed sphere.
acme is used to represent the interval of peak values in climate or environmental record that is contained within the LIG
AHP = African Humid Period
AMSL = Above Mean Sea Level (often shortened to above sea level)
APSL = Above Present Sea Level
CMER = Central MER
CPL = Chinese Loess Plateau
EAM = East African Monsoon
ENA = Early Neoglacial Anomalies
ENSO = El Niño–Southern Oscillation
GHG = Greenhouse Gas
i-cycle = insolation cycles
ITCZ = Intertropical Convergence Zone
LIG = Last Interglacial
LNA = Late Neoglacial Anomalies
M = Magnitude of Earthquake (≥7 is severe damages)
MCO = Miocene Climatic Optimum
MER = Central Ethiopian Rift
MSC = Messinian Salinity Crisis
MSL = Mean sea level (often shortened to sea level)
NH = Northen Hemisphere
NP = North Pole
p-cycle = precession cycles
PIG = Present Interglacial
QBO = Quasi‐biennial Oscillation
SH = Southern Hemisphere
SP = South Pole
SPCZ = South Pacific Convergence Zone
SST = Sea-Surface Temperature
UV = Ultraviolet
VEI = Volcano Explosivity Index (1-10 km3 for VEI = 5, 10—100 km3 for VEI = 6, and 100-1000 km3 for VEI = 7)
WAM = West African Monsoon
WD = Western Disturbances
CE = Comon Era / Current Era
AD = Anno Domini
BC / BCE = Before Comon Era / Before Current Era
14C = Carbon 14 dating, radiocarbon years
cal yr = calendar years / calibrated years
yr = year(s)
BP = Before Present; standard practice is to use 1 January 1950 as commencement date of the age scale
a = annum, age
cal BP = calibrated years befor present
ka / kya = kiloyears ago, thousend years ago
ma / mya = million years ago
ga / bya = billion years ago
b2k = was introduced together with the GICC05 timescale and means years before year two thousend
Large amplitude departures of the Earth magnetic field from the geocentric axial dipole configuration were recorded in geological archives. They correspond to 1) full reversals followed by lasting stable polarity chrons or subchrons, and 2) aborted, i.e. transient or incomplete, reversals called excursions, followed by a re-stabilization in the initial polarity (e.g. Laj and Channell, 2015) [Q. Simon et al., 2018].
The basic magnetostratigraphical unit is the magnetic zone or magnetozone, which usually is identified as a rock interval characterised by a specific (either normal or reverse) dominant magnetic polarity. The interval of time corresponding to a particular magnetic polarity zone is the magnetic chron, which has a typical duration of about 105 to 107 years. Subchrons are shorter intervals of opposing polarity within a chron and superchrons are longer intervals of dominantly normal, reverse or mixed polarity. Small scale perturbations in ocean floor magnetic polarity records which may represent very short geomagnetic polarity events are called cryptochrons [International Commission on Stratigraphy, from: http://quaternary.stratigraphy.org/stratigraphic-guide/magnetostratigraphy/, on 14.12.2019, at 12:22].
A geomagnetic excursion is generally defined as a brief, ca. 1–10 ka,period of reduced intensity of the Earth's magnetic field accompanied by a substantial shift in direction away from a geocentricaxial dipole configuration during an otherwise stable polarity chron [B.R. Jicha et al., 2011, DOI:10.1016/j.epsl.2011.08].
The intensity of Earth’s magnetic field varies continuously, and it has decreased by ∼10% over the past century. Short-lived but rapid field changes occur on centennial timescales when the geomagnetic field intensity decreases into a reversal or excursion. Such rapid geomagnetic changes can disturb animal navigation, damage satellites, and disturb radio communications [Yu-Min Chou et al., 2018].
The weakening of the geomagnetic field causes an increase in galactic cosmic ray (GCR) flux. Recent studies have reported geological evidence for a link between weakened geomagnetic field and climatic cooling [Ikuko Kitaba et al., 2017].
The geochronology community’s EarthTime initiative (Schmitz and Kuiper, 2013) spurred major advances in the precision and accuracy of both UePb and 40Ar/39Ar dating by mitigating systematic uncertainties associated with spikes, standards and decay constants [J.E.T. Channell et al., 2020, https://doi.org/10.1016/j.quascirev.2019.106114].
The geomagnetic field is a vector field and three convenient quantities to describe it are declination, inclination, and intensity. Declination is the angle of the vector eastward of geographic north in the horizontal plane. Inclination is the angle between the vector and Earth’s surface (positive downward). The field intensity (strength) is the magnitude of the vector. The term palaeosecular variation (PSV) in general describes variations on centennial timescales and longer, and can be used to provide age constraints on archaeomagnetic materials, volcanic rocks, and sediments on timescales of hundreds to thousands of years. This method of dating is known as archaeomagnetic dating or palaeomagnetic dating [M. Korte et al., 2019, DOI: http://doi.org/10.1016/j.quageo.2018.11.004].