Africa, Plates, Kenny Lienhard

The Plate in detail

Africa, seed 366

Plate 2 of 52 · one of one

Traits

Palette: Jasper
Structure: Anticline
Event: None
Faults: One
Scale: Standard
Hang: Level
Accent: Repeated
Era: Green Sahara
Heading: Northeast, 50.5°
Speed: 3.12 cm a year

History

The past. The Green Sahara: after a first wet spell in the south, grassland, rivers and lakes spread north across the Sahara 11,576 to 9,076 years ago, and Lake Mega-Chad covered about 360,000 square kilometres. The desert came back, north first, 6,576 to 4,876 years ago. Only the desert beds turn to grass, all at once, and only inside those windows.

3.6 billion years ago: Some of the oldest rocks on this plate formed, in the ancient core of the Zimbabwe craton.
340 million years ago: Ocean floor still lying under the eastern Mediterranean may date from this time, which would make it the oldest ocean floor in place on Earth. Its age is debated.
190 million years ago: Northwest Africa and North America pulled apart and the Central Atlantic Ocean began to open.
113 million years ago: Africa and South America broke apart and the South Atlantic Ocean opened, after a long rift.
31 million years ago: A mantle plume erupted flood lavas, and rifts began to tear Arabia away from Africa.
6 million years ago: The Mediterranean was cut off from the Atlantic, and thick salt layers formed as its water evaporated.

Sources: Tierney et al. 2017, Science Advances 3:e1601503; Collins et al. 2017, Nature Communications 8:1372; Hely et al. 2014, Climate of the Past 10:681; Armitage et al. 2015, PNAS 112:8543 · Horstwood et al. 1999, Geology 27:707 · Granot 2016, Nature Geoscience 9:701 · Seton et al. 2020, age grid v2020.1 processed here, Geochemistry Geophysics Geosystems · Labails et al. 2010, Earth and Planetary Science Letters 297:355 · Heine, Zoethout and Muller 2013, Solid Earth 4:215 · Bosworth, Huchon and McClay 2005, Journal of African Earth Sciences 43:334 · Krijgsman et al. 1999, Nature 400:652

Onchain

The file

97,713bytes, the whole work

74,112bytes of code that draws it

7,304bytes of its record, plain text

0network requests

One HTML file, to be etched to Ethereum in full: the code that draws the work (151,144 bytes before compression), this plate’s settings and its record. Nothing is fetched from anywhere else. It reads your clock and slides the view to where the plate is today.

engine sha256 a7fbc03acc0fc9ba343881bb88ddaf2b7564564d8bc9cbed16e75e47e01fb3f2

The record inside it

The plate: Africa, a major plate in Bird’s PB2002 model: 58,475,569 km², 57% ocean
Its motion: A pole at 49.78°N 74.56°W turning 0.283° per million years; at its centre 3.1 cm a year, heading northeast
What covers it: deep ocean 48%, desert 20%, slope and ridge 7%, forest 7%, and nine more
Its past: Green Sahara, between 11,576 and 4,876 years ago, with its account and source
Deep history: Eight dated events, the oldest 3.6 billion years ago, each with its source
Its outline: 150 points, to a hundredth of a degree
Licence: CC0 1.0, no rights reserved

Read the record

Sources

The plate, its outline and its motionBird, P. (2003). An updated digital model of plate boundaries. Geochemistry, Geophysics, Geosystems 4(3), 1027.
What covers it, which chose the paletteESA CCI Land Cover and Water Bodies, ETOPO 2022, Köppen-Geiger climate maps, NSIDC Sea Ice Index.

Africa

Finished