6.14: Accessible Descriptions
- Page ID
- 125294
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\(\newcommand{\avec}{\mathbf a}\) \(\newcommand{\bvec}{\mathbf b}\) \(\newcommand{\cvec}{\mathbf c}\) \(\newcommand{\dvec}{\mathbf d}\) \(\newcommand{\dtil}{\widetilde{\mathbf d}}\) \(\newcommand{\evec}{\mathbf e}\) \(\newcommand{\fvec}{\mathbf f}\) \(\newcommand{\nvec}{\mathbf n}\) \(\newcommand{\pvec}{\mathbf p}\) \(\newcommand{\qvec}{\mathbf q}\) \(\newcommand{\svec}{\mathbf s}\) \(\newcommand{\tvec}{\mathbf t}\) \(\newcommand{\uvec}{\mathbf u}\) \(\newcommand{\vvec}{\mathbf v}\) \(\newcommand{\wvec}{\mathbf w}\) \(\newcommand{\xvec}{\mathbf x}\) \(\newcommand{\yvec}{\mathbf y}\) \(\newcommand{\zvec}{\mathbf z}\) \(\newcommand{\rvec}{\mathbf r}\) \(\newcommand{\mvec}{\mathbf m}\) \(\newcommand{\zerovec}{\mathbf 0}\) \(\newcommand{\onevec}{\mathbf 1}\) \(\newcommand{\real}{\mathbb R}\) \(\newcommand{\twovec}[2]{\left[\begin{array}{r}#1 \\ #2 \end{array}\right]}\) \(\newcommand{\ctwovec}[2]{\left[\begin{array}{c}#1 \\ #2 \end{array}\right]}\) \(\newcommand{\threevec}[3]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \end{array}\right]}\) \(\newcommand{\cthreevec}[3]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \end{array}\right]}\) \(\newcommand{\fourvec}[4]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \\ #4 \end{array}\right]}\) \(\newcommand{\cfourvec}[4]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \\ #4 \end{array}\right]}\) \(\newcommand{\fivevec}[5]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \\ #4 \\ #5 \\ \end{array}\right]}\) \(\newcommand{\cfivevec}[5]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \\ #4 \\ #5 \\ \end{array}\right]}\) \(\newcommand{\mattwo}[4]{\left[\begin{array}{rr}#1 \amp #2 \\ #3 \amp #4 \\ \end{array}\right]}\) \(\newcommand{\laspan}[1]{\text{Span}\{#1\}}\) \(\newcommand{\bcal}{\cal B}\) \(\newcommand{\ccal}{\cal C}\) \(\newcommand{\scal}{\cal S}\) \(\newcommand{\wcal}{\cal W}\) \(\newcommand{\ecal}{\cal E}\) \(\newcommand{\coords}[2]{\left\{#1\right\}_{#2}}\) \(\newcommand{\gray}[1]{\color{gray}{#1}}\) \(\newcommand{\lgray}[1]{\color{lightgray}{#1}}\) \(\newcommand{\rank}{\operatorname{rank}}\) \(\newcommand{\row}{\text{Row}}\) \(\newcommand{\col}{\text{Col}}\) \(\renewcommand{\row}{\text{Row}}\) \(\newcommand{\nul}{\text{Nul}}\) \(\newcommand{\var}{\text{Var}}\) \(\newcommand{\corr}{\text{corr}}\) \(\newcommand{\len}[1]{\left|#1\right|}\) \(\newcommand{\bbar}{\overline{\bvec}}\) \(\newcommand{\bhat}{\widehat{\bvec}}\) \(\newcommand{\bperp}{\bvec^\perp}\) \(\newcommand{\xhat}{\widehat{\xvec}}\) \(\newcommand{\vhat}{\widehat{\vvec}}\) \(\newcommand{\uhat}{\widehat{\uvec}}\) \(\newcommand{\what}{\widehat{\wvec}}\) \(\newcommand{\Sighat}{\widehat{\Sigma}}\) \(\newcommand{\lt}{<}\) \(\newcommand{\gt}{>}\) \(\newcommand{\amp}{&}\) \(\definecolor{fillinmathshade}{gray}{0.9}\)Earth's Interior
| Material | S Wave (kilometers per second) | P Wave (kilometers per second) |
|---|---|---|
| Dry sand | 0.1 to 0.4 | 0.4 to 1.3 |
| Clay | 0.2 to 0.6 | 0.6 to 1.6 |
| Wet sand | 0.7 to 0.8 | 1.5 to 2.2 |
| Till | 0.8 to 1.0 | 1.9 to 2.6 |
| Mudstone | 2.1 to 2.3 | 3.0 to 4.3 |
| Sandstone | 1.4 to 2.5 | 3.0 to 5.0 |
| Limestone | 2.4 to 3.1 | 4.2 to 5.8 |
| Granite | 3.0 to 3.7 | 4.9 to 5.9 |
| Basalt | 3.3 to 4.0 | 5.2 to 6.2 |
| Layer | Depth from surface (km) | S-Wave velocity (kilometers per second) | P-Wave velocity (kilometers per second) |
|---|---|---|---|
| Crust | 0 to 30 | 3.0 to 4.6 | 5.3 to 7.0 |
| Lithosphere | 30 to 100 | 4.6 to 5.8 | 7.0 to 8.7 |
| Asthenosphere | 100 to 250 | 5.0 to 5.9 | 7.8 to 8.5 |
| Mantle | 250 to 2890 | 5. to 7.0 | 8.2 to 12.6 |
| Outer core | 2890 to 5100 | 0 | 8.0 to 10.1 |
| Inner core | 5100 to 6370 | 0 | 11.8 to 12.0 |
Geologic Time
| Number of half-lives | Percent of 40K remaining | Percent of 40Ar |
|---|---|---|
| 0 | 100 | 0 |
| 1 | 50 | 50 |
| 2 | 25 | 75 |
| 3 | 12.5 | 87.5 |
| 4 | 6.25 | 93.75 |
| 5 | 3.125 | 96.875 |
| 6 | 1.5625 | 98.4375 |
| 7 | 0.78125 | 99.21875 |
| Proportion of Potassium-40 remaining | Age (in millions of Years) |
|---|---|
| 1.00 | 0 |
| 0.99 | 19 |
| 0.98 | 37 |
| 0.97 | 55 |
| 0.96 | 75 |
| 0.95 | 96 |
| 0.94 | 114 |
| 0.93 | 134 |
| 0.92 | 156 |
| 0.91 | 175 |
| 0.90 | 194 |
| Era | Period | Time span |
|---|---|---|
| Paleozoic | Cambrian | 488 to 540 Ma |
| Paleozoic | Ordovician | 488 to 444 Ma |
| Paleozoic | Silurian | 444 to 416 Ma |
| Paleozoic | Devonian | 416 to 359 Ma |
| Paleozoic | Carboniferous | 359 to 299 Ma |
| Paleozoic | Permian | 299 to 251 Ma |
| Mesozoic | Triassic | 251 to 202 Ma |
| Mesozoic | Jurassic | 202 to 146 Ma |
| Mesozoic | Cretaceous | 146 to 65.5 Ma |
| Cenozoic | Paleogene | 65.5 to 23 Ma |
| Cenozoic | Neogene | 23 to 2.6 Ma |
| Cenozoic | Quaternary | 2.6 Ma to present |
| Period | Epoch | Time span |
|---|---|---|
| Paleogene | Paleocene | 65.5 to 55.8 Ma |
| Paleogene | Eocene | 55.8 to 33.9 Ma |
| Paleogene | Oligocene | 33.9 to 23.0 Ma |
| Neogene | Miocene | 23.0 to 5.3 Ma |
| Neogene | Pliocene | 5.3 to 2.6 Ma |
| Quaternary | Pleistocene | 2.6 Ma to 11,700 years ago |
| Quaternary | Holocene | 11,700 years ago to the present |
Figure \(\PageIndex{1}\) image description: The Hadean eon (3800 Ma to 4570 Ma), Archean eon (2500 Ma to 3800 Ma), and Proterozoic eon (542 Ma to 2500 Ma) make up 88% of geological time. The Phanerozoic eon makes up the last 12% of geological time. The Phanerozoic eon (0 Ma to 542 Ma) contains the Paleozoic, Mesozoic, and Cenozoic eras. [Return to Figure \(\PageIndex{1}\)]