Difference between revisions 1655210 and 1655212 on enwikiversity

[[Image:Ice cap.jpg|thumb|right|200px|This is an aerial image of the ice cap on Ellesmere Island, Canada. Credit: National Snow and Ice Data Center.]]
'''Earth''' is rocky astronomical object, a liquid object, a gaseous object, and a plasma object.
{{clear}}

==Astronomy==
{{main|Astronomy}}
[[Image:Greenland 42.74746W 71.57394N.jpg|thumb|right|200px|Satellite composite image shows the ice sheet of Greenland. Credit: NASA.]]
(contracted; show full)

"The near-infra-red snow albedo is sensitive to changes in characteristic snow grain size. Spectral measurements show a distinct drop in the near-infra-red albedo as the snow metamorphoses, i.e. the grain size increases. The visible albedo is little affected by the variation of grain size. Clouds affect the snow albedo by introducing a spectral shift to the incoming radiation. It is shown that the
		  integrated		  snow albedo (370-900 nm) increases by 7% due to the change from clear sky to overcast weather."<ref name=Winther/>
{{clear}}

==Microwaves==
{{main|Radiation astronomy/Microwaves|Microwave astronomy}}
(contracted; show full)
[[Image:Landsat Thematic Mapper Manitouwadge.jpg|thumb|right|200px|This is a Landsat Thematic Mapper image with overlain geological structures. Credit: I.M. Kettles, A.N. Rencz, and S.D. Bauke.]]
"Approximately five million tonnes were mined from native copper deposits in Michigan. Copper masses from the Michigan deposits were transported by the Pleistocene glaciers. Areas on the copper surfaces which appear to represent glacial abrasion show minimal corrosion."<ref name=Johnson
1980>{{ cite journal
|author=A.B. Johnson Jr. and B. Francis
|title=Durability of metals from archaeological objects, metal meteorites, and native metals
|publisher=Battelle Pacific Northwest Laboratories, Department of Energy
|location=Richland, Washington USA
|month=01 January
|year=1980
|editor=
(contracted; show full)
{{clear}}

==Triassic==
{{main|History/Triassic|Triassic}}
[[Image:Triassic Utah.JPG|thumb|right|200px|This middle Triassic marginal marine sequence in southwestern Utah consists of siltstones and sandstones. Credit: [[w:User:Wilson44691|Wilson44691]].]]
The '''Triassic'''/Jurassic boundary occurs at 205.7 ± 4.0 Ma (million years ago).<ref name=Gradstein
/>{{ cite journal
|author=Felix M. Gradstein, Frits P. Agterberg, James G. Ogg, Jan Hardenbol, Paul Van Veen, Jacques Thierry, and Zehui Huang
|title=A Triassic, Jurassic and Cretaceous Time Scale, In: ''Geochronology Time Scales and Global Stratigraphic Correlation''
|volume=SEPM Special Publication No. 54
|publisher=Society for Sedimentary Geology
|location=
|month=
|year=1995
|editor=
|volume=
|issue=
|pages=
|url=http://archives.datapages.com/data/sepm_sp/SP54/A_Triassic_Jurassic_and_Cretaceous_Time_Scale.htm
|arxiv=
|bibcode=
|doi=1-56576-024-7
|pmid=
|isbn=
|accessdate=2017-02-09 }}</ref>

The Permian/'''Triassic''' boundary occurs at 248.2 ± 4.8 Ma (million years ago).<ref name=Gradstein/>
{{clear}}

==Structural geology==
{{main|Earth/Geology/Structures|Structural geology}}
[[Image:Quebrada de Cafayate, Salta (Argentina).jpg|thumb|right|200px|The image shows rock strata in Cafayate, Argentina. Credit: travelwayoflife.]]
(contracted; show full){{Astronomy resources}}{{Sisterprojectsearch}}

<!-- categories -->
[[Category:Astronomy/Lectures]]
[[Category:Astronomy learning projects/Lectures]]
[[Category:Earth/Lectures]]
[[Category:Planetary sciences/Lectures]]
[[Category:Resources last modified in February 2017]]