Main article: Roseanne Conner. Played by Roseanne Barr. Roseanne, in a takeoff of her stand-up comedic and presumed real-life persona, is a bossy, loud, caustic, overweight, and dominant woman. She constantly tries to control the lives of her sister, husband, children, co-workers, and friends.
Where Does Volcanic Activity Occur? Myth: Most of the Earth's igneous rocks are produced at the Ring of Fire.. Fact: 70% of the Earth's surface is ocean floor, which is made of basalt, an igneous rock produced at mid-ocean ridges. The ridges are the most volcanically active features on the planet. Plate boundary volcanism. Volcanic activity occurs at two types of plate boundaries: mid-ocean ridges and subduction zones. At mid-ocean ridges, basaltic eruptions produce new sea-floor crust. These underwater eruptions don't produce big mountainous volcanoes, which is why they are often overlooked as the most volcanically active features on Earth.
Spreading center volcanism occurs at the site of mid-oceanic ridges, where two plates diverge from one another. As the plates are pulled apart, hot asthenosphere rises upward to fill voids of the extended lithosphere. The rise of this hot mantle provides thermal buoyancy to the ridge area and this is the reason that they stand as high ridges in the center of ocean basins. This is demonstrated in the colored relief images shown here. Mid-oceanic ridge of the south Pacific. As the hot asthenosphere rises to shallow levels, it decompresses and melts to produce basalt magmas. These magmas pond in crustal magma chambers where they are periodically tapped by vertical fractures that provide conduits for the rapid rise of magma to the surface.