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Figure Repository

This Figure repository is free-to-use. However, we appreciate mentioning and referring to www.cyclostratigraphy.org.

Introduction to the figure repository

Here we collect the figures that we made specifically for the teaching materials on www.cyclostratigraphy.org. These materials are free to use and adjust, but we appreciate mentioning www.cyclostratigraphy.org as source. Images are displayed as.png files, and can be downloaded as vector.pdf files for easy adjustment.

A compilation of the files for the Introductory lecture can be found as .zip archive here.

Please let us know if you have comments on these materials.

 

Transects through a carbonate platform, illustrating the evolution of facies distribution under slow sea level rise (step 1-2), then rapid sea level rise (step 3) and then a sea level drop (Step 4). The vertical depositional sequences can simulatenously exhibit aggrading, prograding and/or deepening-upward trends, depending on the lateral position on the carbonate platform, on the carbonate production potential, and on accommodation space.
Transect through a carbonate platform, illustrating how astronomical cycles can influence sediment distribution, as well as carbonate production (benthic and planktic).
The evolution of the periods of precession and obliquity throughout the last 500 million years due to tidal dissipation of energy, as from the models of Berger et al. 1992 and Laskar et al. (2004). The La2004 curve has been extrapolated beyond 250 Ma. Ma = million years ago; kyr = thousand years.
Time series of incoming solar radiation on June 21st (Northern Hemisphere summer solstice) at 65°N, between 1 million year ago (right-hand side) and 1 million year in the future (left-hand side). ka = thousand years ago.
The evolution of the three astronomical parameters (eccentricity, obliquity and precession) over the last 1 million year, in the time-domain (middle panels), as well as in the frequency domain (right-hand panels). The representation of the astronomical parameters in the frequency domain is particularly useful to discern their main periodic components: 405 and ~100 kyr for eccentricity, 41 kyr for obliquity and 23, 21 and 19 kyr for precession. ka = thousand years ago. kyr = thousand years duration.
Comparison of exaggerated high-eccentricity (full line) and a low-eccentricity (dashed line) orbit. On a circular orbit, a planet’s angular velocity is constant. On an elliptical orbit, the planet travels faster when closer to the Sun, and slower when farther from the Sun (Kepler’s second law). The length of the blue lines represents the planet’s velocity. Inspired by Mosby, 2005.
The orbit of every planet is an ellipse with the Sun at one of the two foci. Under today’s eccentricity, the perihelion is 147 million kilometres from the Sun, while the aphelion is 152 million kilometres from the Sun. The length of the semi-major axis of the orbit stays constant with changing eccentricity.
The Earth’s precessional movement can be compared to that of a spinning top. Today, the Earth’s rotational axis points towards the North Star. Half a precession cycle later (~10,000 years), the Earth’s rotational axis will point towards Vega. Inspired by Jerome Noir.
The Earth’s rotational axis is tilted, which causes seasonality. By definition, the two solstices happen when the Earth’s rotational axis is pointing directly towards or away from the Sun, which is in June and December. In the Northern Hemisphere, the June solstice marks the start of summer and solar radiation falls perpendicular upon the Tropic of Cancer. The December solstice marks the start of winter and the Sun is directly overhead at the Tropic of Capricorn. The equinoxes happen in March and September. These are the days when the Sun is exactly above the Equator, causing 12 hours of daylight and 12 hours of night everywhere on Earth.
The current precessional configuration makes that Earth is close to the aphelion during summer solstice (June 21st). The precessional movement causes an apparent rotation of the solstices and the equinoxes in the direction of the red arrow. This makes that in about half a precession cycle (~10 000 years), the Earth will be close to the perihelion on June 21st. Inspired by Eelco Rohling.
Precession determines on which day of the year Earth reaches perihelion and aphelion. The effect of precession is thus largest when there is a large difference in Earth-Sun distance between perihelion and aphelion, i.e. under high-eccentricity orbits. Therefore, one can say that the effect of precession is amplitude modulated by eccentricity. This amplitude modulation (red line) is reflected in the precession index or climatic precession (blue line). ka = thousand years ago.
The Earth’s rotational axis is tilted, which causes seasonality. The two solstices happen in June and December, when the Earth’s rotational axis is pointing directly towards or away from the Sun. In the Northern Hemisphere, solar radiation falls perpendicular upon the Tropic of Cancer during the June solstice, latitudes north of the Arctic circle have 24 hours of daylight, and latitudes south of the Antarctic circle have 24 hours of darkness. In the Southern Hemisphere, the Sun is directly overhead at the Tropic of Capricorn during the December solstice, latitudes north of the northern Arctic circle have 24 hours of darkness, and latitudes south of the southern Antarctic circle have 24 hours of daylight. Inspired by Ruddiman: Earth's Climate: Past and Future.
The Earth’s rotational axis is tilted, which causes seasonality. The two solstices happen in June and December, when the Earth’s rotational axis is pointing directly towards or away from the Sun. In the Northern Hemisphere, solar radiation falls perpendicular upon the Tropic of Cancer during the June solstice, latitudes north of the Arctic circle have 24 hours of daylight, and latitudes south of the Antarctic circle have 24 hours of darkness. In the Southern Hemisphere, the Sun is directly overhead at the Tropic of Capricorn during the December solstice, latitudes north of the northern Arctic circle have 24 hours of darkness, and latitudes south of the southern Antarctic circle have 24 hours of daylight. Inspired by Ruddiman: Earth's Climate: Past and Future.
The Moraines of Wallowa Lake (Oregon, USA) not only constitute a wonderful glacial landscape, they also delineate the maximum ice sheet extent during the most recent glacial period (last glacial maximum, ~19 thousand years ago).
The oxygen isotope composition of deep-sea benthic foraminifera is a useful proxy for the evolution of global climate and ice volume. The Lisiecki and Raymo (2005) isotope stack is a composite record from globally-distributed benthic 18O records, providing insights in the dynamics of glacial-interglacial cycles from the Pliocene to the recent (last 5.5 million years). The Mid-Pliocene Warm Period (MPWP) is often used as an analogue for anthropogenic climate warming, as it is the most recent geologic interval with significantly warmer temperatures compared to today. MIS = Marine Isotopic Stages; Brunhes, Matuyama, Gauss and Gilbert refer to magnetostratigraphic chronozones. ka = thousand years ago.
The co-evolution and strong coupling of atmospheric CO2 and Antarctic temperature over the last 800 thousand years as measured in Antarctic ice cores. ka = thousand years ago.
Temperature data from Jouzel, J., et al. 2007. doi: 10.1002/2014GL061957;
IGBP PAGES/World Data Center for Paleoclimatology Data Contribution Series # 2007-091, accessed 13th Nov2020, NOAA/NCDC Paleoclimatology Program, Boulder CO, USA.
ftp://ftp.ncdc.noaa.gov/pub/data/paleo/icecore/antarctica/epica_domec/edc3deuttemp2007.txt
CO2 data: Lüthi et al. 2015, doi: 10.1038/nature06949;
Bereiter et al. 2015, doi: 10.1002/2014GL061957;
IGBP PAGES/World Data Center for Paleoclimatology Data Contribution study 17975, accessed 13th Nov2020, NOAA/NCDC Paleoclimatology Program, Boulder CO, USA.
https://www.ncdc.noaa.gov/paleo/study/17975
Cartoon illustration of enhanced summer monsoon circulation when low-latitude summer insolation is high. Inspired by Ruddiman: Earth's Climate: Past and Future.
Cartoon illustration of the effect of precessional cycle on monsoonal circulation. In the Northern Hemisphere, low-latitude summer insolation is enhanced during a precession minimum, which in turn spurs the summer monsoon. Due to the associated increase in seasonal contrast, also the winter monsoonal circulation is intensified but this does not lead to more precipitation on land. In the Southern Hemisphere, the effect of precession is opposite. Inspired by Ruddiman: Earth's Climate: Past and Future.
Cartoon illustration of the effect of the North-African summer monsoon on Mediterranean Sea circulation. During a strong precession minimum, precipitation over North-Africa and Nile run-off increase, causing a low-salinity lid on the Mediterranean Sea and preventing deep-water formation. Oxygen-poor bottom conditions develop and result in the deposition of an organic-rich sapropel. In addition, enhanced run-off provides additional nutrients and allows enhanced surface-water productivity. More organic material will thus rain down from the surface waters, which will be oxidized at depth further reducing oxygen-levels at depth. Inspired by Ruddiman: Earth's Climate: Past and Future.
Green Sahara in North Africa around ~125 000 years ago, during a simultaneously-occurring extreme precession minimum and obliquity maximum. The cyclic greening of the Sahara, by virtue of cyclic increases of summer monsoon precipitation, may have favoured migration out of Africa with successive ways 20,000 years apart. Inspired by YNot1989 on DeviantArt.com.
The evolution of the three astronomical parameters (eccentricity, obliquity and precession) is often combined into an eccentricity-tilt-precession (ETP) composite signal, by normalizing and adding the three astronomical parameters. The use of an ETP composite does not require a choice of latitude or time of the year, as is the case for insolation series. Moreover, and contrary to insolation signals, the ETP composite contains a direct imprint of eccentricity. The dominant periodicities of the ETP composite can be discerned in the evolutive wavelet power spectrum (lower panel).
Astronomical tuning is the process of correlating cycles in proxy records to an astronomical target curve. Here, a marine oxygen-isotope proxy record is tuned to the June 65°N summer insolation curve. Major deglaciations are tuned to the first strong insolation maximum following an interval of low-amplitude variability (corresponding to eccentricity minima). This astronomical tuning provides precise and accurate numerical ages for the deglaciations, oxygen isotope records and various other proxy records, and is used to calibrate the timing of magnetic reversals and bio-events. Inspired by Ruddiman: Earth's Climate: Past and Future.
Tuning of the youngest sapropels in the Mediterranean in Core RC9-181. Individual sapropels correspond to precession minima, and thus to summer insolation maxima and intensified summer monsoon circulation. Small groups of sapropels (up to 4 sapropels) correspond to ~100-kyr eccentricity maxima, while large group of sapropels correspond to 405-kyr eccentricity maxima. Some sapropels are somewhat thicker (e.g. S8), and correspond to extreme summer insolation maxima due to the added effect of obliquity. The absence of sapropels indicates low precession amplitudes, and thus moderate monsoon intensities, during eccentricity minima.