Sea+Floor+Spreading


 * 3a. Students know features of the ocean floor (magnetic patterns, age, and sea-floor topography) provide evidence of plate tectonics.



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the ocean floor re-creates its self every 200,000 years by the process known as sea floor spreading. Magma rises up out of the mid ocean ridge and is sub ducted back into the center of the earth through its convergent plate boundaries known as seduction zones. Pillow like rocks, magnetic striping, sonar, and drilling are evidence that sea floor spreading occurs. Sea-floor spreading is the process in which the ocean floor is extended when two  [|plates]  move apart. As the [|plates]  move apart, the rocks break and form a crack between the  [|plates]  . Earthquakes occur along the plate boundary. [|Magma] rises through the cracks and seeps out onto the ocean floor like a long, thin, undersea  <span style="font-family: "Calibri","sans-serif"; font-size: 11.0pt; line-height: 115%; mso-ansi-language: EN-US; mso-ascii-theme-font: minor-latin; mso-bidi-font-family: "Times New Roman"; mso-bidi-language: AR-SA; mso-bidi-theme-font: minor-bidi; mso-fareast-font-family: Calibri; mso-fareast-language: EN-US; mso-fareast-theme-font: minor-latin; mso-hansi-theme-font: minor-latin;"><span style="color: black; font-family: "Arial","sans-serif"; font-size: 12.0pt; line-height: 115%; mso-themecolor: text1; text-decoration: none; text-underline: none;">[|volcano]  <span style="color: black; font-family: "Arial","sans-serif"; font-size: 12.0pt; line-height: 115%; mso-ansi-language: EN-US; mso-bidi-language: AR-SA; mso-fareast-font-family: Calibri; mso-fareast-language: EN-US; mso-fareast-theme-font: minor-latin; mso-themecolor: text1;">. **