Data mining and_visualization_of_earth_history_datasets_to_find_cause_effect_relationship
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To know the future of our earth, we need to look back to the past and collect evidence and examine the geologic and biologic events. My projects with http://timescalecreator.org is our approach to analyze the largest publicly available earth historical data to test different hypothesis, to understand better about the past of our loving pale blue. Interestingly lots of the events under the surface of the earth or under the ocean show same periodic cycles that we see in the planetary motions in the solar system and even in the galaxy. Cyclostratigraphy is a field where we try to explore data from the rock or marine records and find possible orbital forcing. Everything is connected after all and we are star dusts !! ;)
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Data mining and_visualization_of_earth_history_datasets_to_find_cause_effect_relationship
- 1. DATA MINING AND VISUALIZATION OF EARTH HISTORY DATASETS TO FIND CAUSE-EFFECT RELATIONSHIP Abdullah Khan Zehady Department of Earth, Atmospheric & Planetary Science, Purdue University.
- 4. Research Projects 1. Macro and micro scale evolution of planktonic foraminifera and the potential drivers during Cenozoic era (66.04 Ma). Hypothesis: “Rates of evolution are correlated with rates of geochemical and sea-level change.” - Can we find long term (2-5 myr) astronomical cycles? 2. Periodicities and other cause-effect relationships among pulses of evolution since Cambrian period (541 Ma). Hypothesis: (a) “The Earth has had semi-periodic episodes of unusual surface/biological change.” - Abundance of events over time; verification of catastrophe models (20 – 60 myr periods); causation by impact and other disastrous events. (b) “Pulses of biological evolution occur simultaneously with global changes in sediment facies.” 3. Effect of climate change on cultural turnover of last 2000 years of human civilization. Hypothesis: “A major factor in the rise and fall of human civilization in different continents is climate cooling.” 4. Automated fossil image recognition by feature extraction using deep neural network. 4
- 5. Project 1 1. Macro and micro scale evolution of planktonic foraminifera and the potential drivers during Cenozoic era (66.04 Ma). Hypothesis: “Rates of evolution are correlated with rates of geochemical and sea-level change.” - Can we find long term (2-5 myr) astronomical cycles? 5 Cenozoic
- 6. Cenozoic Foraminifer Evolution Data Dataset Reference 1. Morphospecies evolutionary tree of Cenozoic planktonic foraminifera coloured and labeled by ecogroup, morphogroup or genus. (340 morphospecies and their first and last appearances) (Aze et al 2011) (Fordham, Zehady et al 2018)2. Lineage tree of Cenozoic planktonic foraminifera coloured and labeled by ecogroup, morphogroup or genus. (214 species and their first and last appearances) 3. Oxygen-18 curves and events (29,000 data points) (Cramer 2009) 4. Carbon-13 curves and events (29,000 data points) 5. Sea-level synthesis curve (648 data points on short-term sea level curve) (Haq et al 2014, 2017) Cenozoic 6
- 7. My papers on evolution and tree visualization To be sumbitted at BMC Evolutionary Biology Cenozoic 7
- 8. Cenozoic Foraminifer Evolution Tree Cenozoic (Fordham, Zehady et al 2018) 8
- 9. Morphospecies and Lineage evolution Cenozoic (Fordham, Zehady et al 2018) 9
- 10. Morphospecies and Lineage concept Cenozoic (Fordham, Zehady et al 2018) 10
- 12. Speciation and Extinction driven by global warming Decreasing oxygen isotope values indicate warming of the surface ocean K/T boundary End of Dinosaurs, Rise of Mammals Paleocene- Eocene Thermal Maximum (PETM ~55 Ma) Cenozoic Chimpanzee divergence, Origin of hominoids Global Cooling, Himalaya, Appearance of Glaciers, Antarctic Icesheet (Eocene- Oligocene boundary 34 Ma) Pliocene Diversity (5.33 Ma) 12 Mid Miocene
- 13. Speciation and Extinction driven by global warming Paleocene- Eocene Thermal Maximum (PETM ~55 Ma) Cenozoic Global Cooling, Himalaya, Appearance of Glaciers, Antarctic Icesheet (Eocene- Oligocene boundary 34 Ma) m) 13 Mid Miocene
- 14. Periodicity in Cenozoic foraminifer evolution Astronomical Forcing.. 2 – 6 myr cycles !! Same 2.4 myr eccentricity cycle in carbon and oxygen isotope record (Kocken et al 2018) Freq (1/myr) Period (myr) AR-1 Confidence Level (%) 0.409 2.4 ~95% 14Frequency (1/myr) Frequency (1/myr) Frequency (1/myr) Harmonic F-test Confidence Level Estimate Autoregressive Model (AR-1) Confidence Level Estimate LinearPowerConfidenceLevelConfidenceLevel Multiper Spectral Power(black), AR1-fit, 90%, 95%, 99% CL Cenozoic
- 15. Orbital forcing - Milankovitch Cycles 15 Amplitude modulation, 2.4 Ma eccentricity cycle
- 16. Project 2 2. Periodicities and other cause-effect relationships among pulses of evolution since Cambrian period (541 Ma). Hypothesis: (a) “The Earth has had semi-periodic episodes of unusual surface/biological change.” - Abundance of events over time; verification of catastrophe models (20 – 60 myr periods); causation by impact and other disastrous events. (b) “Pulses of biological evolution occur simultaneously with global changes in sediment facies.” 16
- 17. 500 myr of micro and macro evolution and underlying factors 17 Phanerozoic
- 18. 500 myr of Geochemical Proxy and Evolution Data Dataset Description 1. Marine genera ranges (18,000 genera ranges ) Through Phanerozoic based on the compendium by Jack Sepkoski that was published in 2002 2. Regional biostratigraphy and basin lithostratigraphy (More than 300 lithology columns) Regions include Australia, New Zealand, China, India, Malaysia, Africa, Britain, Belgium, South America, USA-Alaska, Canada, Mexico, Russia. 3. Phanerozoic(0~541 Ma) sea level curve Computed as mid-point of Coastal-onlaps. (SEPM charts, 1998), CRET (2015) = Revised from: Haq, B.U., 2014. 4. Carbon-13 curve for Phanerozoic Collected from various sources for different geologic periods. 5. Strontium 87/86 ratio Reflects the rate of oceanic spreading and continental erosion. John McArthur (2004). 6. Global trends, Impacts, Volcanism, Tectonics Carbonate trends, Global and regional impact events, super, major and regional LIP events etc. 7. Other geochemical data: P, Si, S, Forg Phosphorus data: Föllmi (1995). Sulfur isotope data: Veizer et al. 1999; Prokoph et al., 2008) 18 Phanerozoic
- 19. 500 Million years of Earth history events 19 Phanerozoic
- 20. Geochemical Indicators with evolution 20 (A) Tectonic (Wilson) cycle - Habitat availability and variability (B) Area of sedimentary rock (Meyers and Peters, 2011) (C) Genus level diversity (Alroy 2018) (D) DROP: Dissolved Reactive Ocean Phosphorus, OAE: Oceaninc Anoxic Events CAMP: Central Atlandic Magmatic Province (E) Strontium istope ratio – continental weathering and runoff. (F) Diversity of green/red phytoplankton, coccolithophorids, dinoflagellates, diatoms. (G) Evolution of terrestrial floras (Cleal and Cascales-Mi-yana, 2014) (H) Area of volcanics (Bluth and Kump, 1991) (I) Bioturbation rates Phanerozoic (NSF Proposal 2017)
- 21. LIP events, ~ 60 myr Periodic Catastrophe 15 Phanerozoic (Prokoph et al 2013) LIP: Large Igneous province (volcanic eruption => Kisses of death)
- 22. Cross-Correlation and Periodicity in Geochemical Indicators • Cross-correlations and periodicities (parentheses) of indices including sea level. • Statistically significant (p<0.05) small-to-moderate positive cross- correlations of ±0.2 or greater for ~25-to-60 myr durations, despite variation in database. 22 LIP: Large Igneous Province (Wignall 2001) Forg: Fraction of carbon buried as organic carbon (Hayes et al 1999) Gen Orig: Marine Genera origination rate (Prokoph et al 2014) 𝑥𝑖 : i-th point in 1st timeseries 𝑦𝑖 : i-th point in 2nd timeseries Correlation co-efficient with lag m : 𝑡 = 𝑟 𝑚 𝑛 − 2 1 − 𝑟 𝑚 2 p-value for a given m is given by a t-test with n-2 degrees of freedom. 𝑟 𝑚 = 𝑥𝑖 − 𝑥 (𝑦𝑖−𝑚 − 𝑦 𝑥𝑖 − 𝑥 2 𝑦𝑖−𝑚 − 𝑦 2 Phanerozoic (NSF Proposal 2017) Corr. 𝑟 𝑚 Periodicity
- 23. Project 3 3. Effect of climate change on cultural turnover of last 2000 years of human civilization. Hypothesis: “A major factor in the rise and fall of human civilization in different continents is climate cooling.” 23 Culture
- 24. Global Cultural turnover and Climate Data Dataset Duration Reference 1. Global Cultural Turnover Events Largest (> 150 event columns) publicly available regional cultural data 0-2000 AD TSCreator Human Culture datapack 2. Central European Temperature Anomaly 1-1990 AD (Büntgen et al., 2011) 3. Stacked (91 proxies) Northern Hemisphere Temperature Anomaly 0-1973 AD (Christiansen et al., 2012) 4. Tree ring based Northern Hemisphere temperature reconstruction using RCS(Regional Curve Standardization) method 713-2004 AD (D'Arrigo et al., 2006) 5. δ18O temperature-proxy from Northern Greenland ice core 0 – 122 Ka (0-2000AD used) (Seierstad et al., 2014) 24 Culture
- 25. Human Cultural Stage • Iron age • Production of iron based tools and weaponry • Bronze age • Copper mined and alloyed with tin to produce bronze • Far-ranging trade network • Neolithic • New stone age • Progression of behavioral and cultural changes • Mesolithic • Pre-agricultural material in northwest europe • Material from Levant • Levant: Large area in east mediterranean • Late Paleolithic 25 Culture
- 26. 2000 years of human cultural turnover 26 Culture
- 27. Region wise cultural turnover events 27 Culture
- 28. Temperature Change in China during Past 2000 Years (Ge et al. 2017) Warm Period (AD) 1. 1 ~ 200 2. 550 ~ 760 3. 950 ~ 1300 4. 1900 ~ Cold Period (AD) 1. 210 ~ 350 2. 420 ~ 530 3. 780 ~ 940 4. 1320 ~ 1900 28 Little Ice Age (LIA) Medieval Warm Period (MWP) Current Warm Period (CWP) Culture Dark Ages Cold Period (DACP)
- 29. Cultural turnovers in China 29 Culture Decreased Total Solar Irradiance (100 yr cycle) Decreased Land temperature Intensified winter monsoon Decreased precipitation and temperature Affects human cultural. (Li et al 2017)
- 30. Climate cooling Decreased land fertility & bio-productivity Decreased agricultural production & food supply Social unrest Low temperature & dry air Low precipitation MigrationWar Lack of co- operation & job scarcity Cultural turnover Reduced riverflow Drought 30 Culture A causal mechanism from cold climate to cultural turnover
- 31. 31 Culture Cultural turnover and temperature timeseries
- 32. Spectral analysis of culture and climate timeseries 32 Culture (a) culture (b) NH Temp (c) Europe Temp (d) NH Temp tree ring (a) Global cultural turnover (b) Stacked Northern Hemisphere temperature anomaly (c) Central European temperature anomaly (d) Tree ring based NH temperature anomaly
- 34. Extra Slides 34
- 35. MAGIC Model 35
- 36. Possible 60 Myr periodicity 36 • Red Curves are intended only to show possible periodicity fitted with the sinusoidal regression. • Minimized Chi-square and Akaike Information Criterion(AIC) to avoid overfitting. Phanerozoic
- 37. Ice Age 37
- 39. Climate + Economic Variables (Li et al 2017) 39
- 40. Disaster + War in North China (Li et al 2017) 40
- 41. Role of Solar activity – Spectral analysis of Temperature Anomaly Increased Total Solar Irradiance Enhanced thermal contrast between East Asian continent and North Pacific ocean Longer summer monsoon in North China More rainfall to North China where surface temperature is higher. Matches with 100, 50, 23 and 22 yr Cycle for solar activity. (Li et al 2017) 41
- 42. European epidemics and War (Zhang et al. 2011b) 42
- 43. Causal Link between Climate Change & Human Crisis (Zhang et al. 2011b) 43
Editor's Notes
- At the boundary between the Palaeocene and Eocene epochs, about 55 million years ago, the Earth experienced a strong global warming event, the Palaeocene–Eocene thermal maximum1–4. The leading hypothesis to explain the extreme greenhouse conditions prevalent during this period is the dissociation of 1,400 to 2,800 gigatonnes of methane from ocean clathrates5,6, resulting in a large negative carbon isotope excursion and severe carbonate dissolution in marine sediments. http://pages.geo.wvu.edu/~kammer/g231/PETM.pdf δ18O is a paleothermometer. Increased values mean colder temperatures, decreased values mean warmer temperatures. δ18O means a change in the amount of 18O in the ratio of 18O/16O, relative to a standard. Typically measured in CaCO3. Background ratio is 1:500. Corresponding to the oxygen isotope shift is a large and negative 4 to 5 per mil change in carbon isotopes that is used to define the geological extent of the event. The isotope excursion has been identified in sediments deposited in the ocean and those laid down in terrestrial environments such as lakes and rivers. It is called a golden spike because it can be correlated around the world and it marks a precise time horizon, in fact, the excursion is now the formal definition of the boundary between the Paleocene and Eocene eras. https://en.wikipedia.org/wiki/Cenozoic https://en.wikipedia.org/wiki/Late_Cenozoic_Ice_Age
- 405 kyr and 2.4 Myr eccentricity components in Cenozoic carbon isotope records Cenozoic stable carbon (δ 13C) and oxygen (δ 18O) isotope ratios of deep-sea foraminiferal calcite co-vary with the 405 kyr eccentricity cycle, suggesting a link between orbital forcing, the climate system, and the carbon cycle. Variations in δ 18O are partly forced by ice-volume changes that have mostly occurred since the Oligocene. The cyclic δ 13C–δ 18O covariations are found in both ice-free and glaciated climate states, however. Consequently, there should be a mechanism that forces the δ 13 5 C cycles independently of ice-dynamics. In search of this mechanism, we simulate the response of several key components of the carbon cycle to orbital forcing in the Long-term Ocean-atmosphere-Sediment CArbon cycle Reservoir model (LOSCAR). We force the model by changing the burial of organic carbon in the ocean with various astronomical solutions and noise, and study the response of the main carbon cycle tracers. Consistent with previous work, the simulations reveal that low frequency oscillations in the forcing are preferentially amplified relative to higher frequencies. However, while oceanic δ 13 10 C mainly varies with a 405 kyr period in the model, the dynamics of dissolved inorganic carbon in the oceans and of atmospheric CO2 are dominated by the 2.4 Myr cycle of eccentricity. This implies that the total ocean and atmosphere carbon inventory is strongly influenced by carbon cycle variability that exceeds the time scale of the 405 kyr period (such as silicate weathering). To test the applicability of the model results, we assemble a long (∼22 Myr) δ 13C and δ 18O composite record spanning the Eocene to Miocene (34 to 12 Ma) and perform spectral analysis to assess the presence of the 2.4 Myr cycle. We 15 find that, while the 2.4 Myr cycle appears to be overshadowed by long-term changes in the composite record, it is is present as an amplitude modulator of the 405 and 100 kyr eccentricity cycles This cyclicity modulates the "2.4 myr eccentricity cycle amplitude, hinting at a possible link 29 between long-term astronomical and geological variations. Some phase shifts between "9- myr !13 30 C and astronomical cycles suggest that additional processes (e.g., tectonics) 31 contribute to these long-term carbon-cycle variations. 32 The strong response of !13 33 C to long-term eccentricity periods ("9 myr, "2.4 myr, "400 34 kyr) supports the hypothesis that the long time-residence of carbon in the oceans amplifies 35 lower frequency or dampens higher frequency orbital variations. Mesozoic greenhouse sequences show some relation with the ~2.4 myr eccentricity cycles, suggesting that orbital forcing contribute to sea-level change. In the 1920s and 1930s, Milutin Milankovitch, a geophysicist, showed that the amount of heatreceived from the sun varied, and that this was related to cyclical changes in the Earth’s orbit. Further, this variation was linked to whether the Earth was in a glacial (colder) or interglacial(warmer) period. It happens when northern hemisphere summers are coolest (the Earth is farthest from the Sun due to precession and eccentricity) and winters are warmest (as a result of minimum axial tilt). This means that snow can accumulate across large areas of the northern land masses. https://www.sciencelearn.org.nz/resources/1036-astronomical-cycles The multitaper method overcomes some of the limitations of conventional Fourier analysis. When applying the Fourier transform to extract spectral information from a signal, we assume that each Fourier coefficient is a reliable representation of the amplitude and relative phase of the corresponding component frequency. This assumption, however, is not always valid. For instance, a single trial represents only one noisy realization of the underlying process of interest. A comparable situation arises in statistics when estimating measures of central tendency i.e., it is bad practice to estimate qualities of a population using individuals or very small samples. Likewise, a single sample of a process does not necessarily provide a reliable estimate of its spectral properties. Moreover, the naive power spectral density obtained from the signal's Fourier transform is a biased estimate of the true spectral content. These problems are often overcome by averaging over many realizations of the same event. However, this method is unreliable with small data sets and undesirable when one does not wish to attenuate signal components that vary across trials. Instead of ensemble averaging, the multitaper method reduces estimation bias by obtaining multiple independent estimates from the same sample. Each data taper is multiplied element-wise by the signal to provide a windowed trial from which one estimates the power at each component frequency. As each taper is pairwise orthogonal to all other tapers, the windowed signals provide statistically independent estimates of the underlying spectrum. The final spectrum is obtained by averaging over all the tapered spectra. Thomson chose the Slepian or discrete prolate spheroidal sequences as tapers since these vectors are mutually orthogonal and possess desirable spectral concentration properties (see the section on Slepian sequences). In practice, a weighted average is often used to compensate for increased energy loss at higher order tapers[2].
- The pattern of incident solar radiation (insolation) received on the planet at a given place and time is an important factor in understanding both directional trends and variability observed in many paleoclimatic records, particularly those related to Quaternary ice ages (Hays et al. 1976, Laskar et al. 2004). Changes in insolation are, in turn, driven by Earth's natural orbital oscillations, termed Milankovitch cycles. The three elements of Milankovitch cycles are eccentricity, obliquity, and precession (Figure 3). Eccentricity describes the degree of variation of the Earth's orbit around the Sun from circular to more elliptical. Eccentricity has two main periodicities, one cycle with an average of ~100,000 years and a longer cycle with a periodicity of ~413,000 years. Obliquity describes the tilt of the Earth's axis in relation to its orbital plane, which ranges from 22.1–24.5 degrees with a periodicity of ~41,000 years. Precession describes the motion of the Earth's axis of rotation, which does not point towards a fixed direction in the sky through time. Instead, the axis of rotation describes a clockwise circle in space, like the spinning of a wobbling top, with a periodicity of 19,000–23,000 years
- A coral reef is an underwater ecosystem characterized by reef-building corals. Reefs are formed of colonies of coral polypsheld together by calcium carbonate. Miocene-paleocene events. Carbonate platform: calcareous deposits Super LIP events - A large igneous province (LIP) is an extremely large accumulation of igneous rocks
- Orogeny and volcanism serve as the primary sources of “new” macronutrients like phosphorus (Wu et al., 2000). The strontium isotope (87Sr/86Sr) record serves as a general, qualitative indicator of nutrient runoff from land Environmental change and diversification of the marine biosphere (adapted and updated fromMartin et al., 2008; Martin and Quigg, 2012). Horizontal gray bars indicate peak biodiversity of the Alroy(2010) curve (Figure 2B ) in relation to other indicators discussed in the text. Tectonic (Wilson)cycles. Area of preserved sedimentary strata in North America during the Phanerozoic (blue), with North American sequences and 56-myr periodicity (red; Meyers and Peters, 2011). C) Genus level diversity of the three macroevolutionary faunas (Alroy, 2010). GOBE = Great Ordovician Biodiversity Event. Note similarity to Figure 2D. Here we use Figure 2B (not 2D), because it differentiates Sepkoski’s faunas. D) MAGic model indices discussed in text: Si and P weathering fluxes and Dissolved Reactive Ocean Phosphorus. OAE = Oceanic Anoxic Events also discussed in text. CAMP = Central Atlantic Magmatic Province. PETM = Paleocene-Eocene Thermal Maximum. Strontium isotope ratios (87 Sr/86 Sr) (Veizer et al., 1999). Increasing ratios are a qualitative indicator of increased continental weathering and runoff. Major glaciations indicated by snowflakes. Diversity of marine eukaryotic phytoplankton. “Green” phytoplankton = acritarchs; “Red” phytoplankto n = coccolithophorids, dinoflagellates, diatoms. Note parallel rise and decline of Paleozoic Fauna and green algal lineage, and diversification of Modern Fauna and red algal lineage during the Meso-Cenozoic. Evolution of major terrestrial floras (Cleal and Cascales-Mi–yana, 2014). Area of volcanics (Bluth and Kump, 1991, after Ronov). Bioturbation rates and infaunal tiering. Red: number of taxa with reworking rates >10cc/day (Thayer, 1983); black: maximum depth (cm) of infaunal tiering below sediment-water interface (dashed line = inferred; after Ausich and Bottjer, 2001). (one of a series of rows or ranks rising one behind or above another, as of seats in an amphitheater, boxes in a theater, guns in a man-of-war, or oars in an ancient galley. one of a number of galleries, as in a theater. a layer; level; stratum: The wedding cake had six tiers.)
- 62 3 the record of marine animal diversity (Rohde and Muller 2005; Cornette 2007; Lieberman and Melott 2007; Melott 2008; Melott and Bambach 2011a). This periodicity is present in three independent sets of data that we have examined that document Phanerozoic marine diversity (details in Melott and Bambach 2011a and references therein). A periodicity of m.yr. is present in the temporal and 58 4 area-weighted number of gap-bound sedimentary carbonate in the United States (Melott and Bambach 2011b, using data from Peters 2008a). Peters (2008b) initially noted that, on the basis of his data, the Sloss Sequences—as Peters had redefined them—averaged 67 m.yr. in length, and he observed that this was similar to the periodicity of diversity fluctuation observed by Rohde and Muller (2005) http://users.clas.ufl.edu/eemartin/GLY5736F07/literature/LIPs-ElementsMag.pdf
- Cross-correlation (Davis 1986)is carried out on two column(s) of evenly sampled temporal/stratigraphic data. The x axis shows the displacement of the second column with respect to the first, the y axis the correlation between the two time series for a given displacement. The "p values" option will draw the significance of the correlation, after Davis (1986). Geochemical indicators. Left column : entire Phanerozoic. (A-B) LIP volumes (0-260Ma; A = minimal value of volume range with oceanic LIPs reduced by ~50% for underplating to better compare with continental LIPs, for which underplating cannot typically be estimated; B =maximum volume including underplating for oceanic LIPs ). (C-E) Sr and sulfur isotope ratios and genera origination rates (0-541 Ma) (all from Prokoph et al., 2014). Right column : Meso- Cenozoic only. (A) Phosphorus accumulation rate (Fšllmi, 1995). (B) Log Percent carbon (Martin et al., 2008, 2012). (C-D) Strontium and sulfur isotope ratios, and (E) genera origination rate (Prokoph et al., 2014). Curves are intended only to show possible periodicities described in text and were fitted with the sinusoidal option of Paleontological Statistical Analysis (PAST) freeware, while minimizing Chi-square and Akaike Information Criterion to avoid overfitting.
- * 4 warm epochs and 4 cold epochs
- Responses of different variables in human society to climate change in Europe, A.D. 1500–1800. (A) NH temperature anomaly (8C, red line) and Europe temperature anomaly (σ, black line). (B) Ratio of grain yield to seed (red line) and NH extratropical tree-ring widths (black line). (C) Detrended grain price (Ag/L, red line) and detrended agricultural production index (black line). (D) Detren- ded wage index (σ, red line) and number of famine years per decade (black line). (E) Number of wars (red line) and magnitude of social disturbances (black line). (F ) Detrended human height (in cm, red line) and number of plagues per decade (black line). (G) War fatality index (red line) and number of migrations per quarter century (black line). (H) Detrended population size (in millions, red line)
- The MAGic model was first described in 2006 (MAGic, Mackenzie, Arvidson, Guidry interactive cycles: Arvidson et al., 2006). An overview of the model is shown schematically in Figure 5. In this model, silicate weathering rates are similar to outgassing rates of volcanic and metamorphic CO2; intervals of continental dispersion are characterized by high rates of outgassing and runoff due to intensification of the hydrologic cycle (Tardy et al., 1989; Föllmi et al., 1993; Gibbs et al., 1999); and phosphorus uptake is directly related to the flux of reactive P from the land through the mean C:N:P ratio of 106:16:1 of marine phytoplankton. Schematic diagram of the Earth system MAGic model showing the major reservoirs and the coupling network. Reservoir sizes are not proportional, and many transfers are generalized. Precipitation fluxes are indicated by blue arrows, weathering or (diagenetic) dissolution by brown, elevated temperature (to hydrothermal) interactions by magenta, and metamorphic or magmatic transfers by red. Basalt and mantle are also distinct in the model, although mantle output flows are held equal to input. Virtually all reservoirs sustain transfers to or from atmospheric CO2 and O2; these are thus omitted for clarity.
- Scientists have recorded five significant ice ages throughout the Earth’s history: the Huronian (2.4-2.1 billion years ago), Cryogenian (850-635 million years ago), Andean-Saharan (460-430 mya), Karoo (360-260 mya) and Quaternary (2.6 mya-present). Approximately a dozen major glaciations have occurred over the past 1 million years, the largest of which peaked 650,000 years ago and lasted for 50,000 years. The most recent glaciation period, often known simply as the “Ice Age,” reached peak conditions some 18,000 years ago before giving way to the interglacial Holocene epoch 11,700 years ago. At the height of the recent glaciation, the ice grew to more than 12,000 feet thick as sheets spread across Canada, Scandinavia, Russia and South America. Corresponding sea levels plunged more than 400 feet, while global temperatures dipped around 10 degrees Fahrenheit on average and up to 40 degrees in some areas. When the eccentricity of Earth's orbit is small, the frequency of climatic precession undergoes large variations and less precession energy is passed through a narrow‐band filter. Furthermore, eccentricity‐like amplitude modulation is routinely obtained from pure noise records that are orbitally tuned to precession and then filtered. We conclude that the presence of eccentricity‐like amplitude modulation in precession‐filtered records does not support the accuracy of orbitally tuned time scales.
- The pattern of incident solar radiation (insolation) received on the planet at a given place and time is an important factor in understanding both directional trends and variability observed in many paleoclimatic records, particularly those related to Quaternary ice ages (Hays et al. 1976, Laskar et al. 2004). Changes in insolation are, in turn, driven by Earth's natural orbital oscillations, termed Milankovitch cycles. The three elements of Milankovitch cycles are eccentricity, obliquity, and precession (Figure 3). Eccentricity describes the degree of variation of the Earth's orbit around the Sun from circular to more elliptical. Eccentricity has two main periodicities, one cycle with an average of ~100,000 years and a longer cycle with a periodicity of ~413,000 years. Obliquity describes the tilt of the Earth's axis in relation to its orbital plane, which ranges from 22.1–24.5 degrees with a periodicity of ~41,000 years. Precession describes the motion of the Earth's axis of rotation, which does not point towards a fixed direction in the sky through time. Instead, the axis of rotation describes a clockwise circle in space, like the spinning of a wobbling top, with a periodicity of 19,000–23,000 years
- 5D & 10K represents the period of Five Dynasties and Ten Kingdoms in China PANN and TANN : Important bioclimatic variables for plant distribution Pollen- based numerical climatic inferences in northern China
- 5D & 10K represents the period of Five Dynasties and Ten Kingdoms in China PANN and TANN : Important bioclimatic variables for plant distribution Pollen- based numerical climatic inferences in northern China
- Correlate well with the 100, 50, 23 and 22 year cycles for the solar activity observed in various solar parameters
- Temperature change and the alternation of periods of harmony and crisis in the NH during the past millennium. (A) European temperature anomaly (σ). (B) NH temperature anomaly (8C). (C) NH annual population growth rate (%). (D) Famine years in the NH (number of famine years per decade). (E) Number of deadly epidemic events (malaria, plague, typhus, measles, smallpox, and dysentery) per decade in the NH. (F) Number of wars per year in the NH. All data were smoothed by a 100-y Butterworth low-pass filter. Gray stripes represent periods of crisis in Europe as delimitated by historians