1.The Ring of Fire is a zone of frequent earthquakes and volcanic eruptions that encircles the basin of the Pacific Ocean. It is shaped like a horseshoe and it is 40,000 km long. It is associated with a nearly continuous series of oceanic trenches, island arcs, and volcanic mountain ranges and/or plate movements. It is sometimes called the circum-Pacific belt or the circum-Pacific seismic belt.
90% of the world's earthquakes and 81% of the world's largest earthquakes occur along the Ring of Fire. The next most seismic region (56% of earthquakes and 17% of the world's largest earthquakes) is the Alpide belt which extends from Java to Sumatra through the Himalayas, the Mediterranean, and out into the Atlantic. The Mid-Atlantic Ridge is the third most prominent earthquake belt.
2..Low salinity water (light blue region at 10-150 north) lies in the polar and subpolar regions and near the equator. The equatorial region of low salinity ocean water lies below an atmospheric region called the "intertropical convergence zoneThe intertropical convergence zone moves about the equator as the intense heat in the equatorial area produces a rising mass of moisture-laden air, thereby creating a region of low atmospheric pressure.
The equatorial low pressure system pulls air and moisture from adjacent regions towards the equator. Consequently, air masses converge in this region from north and south of the equator, bringing moisture acquired by evaporation in the subtropical regions.
The warm, humid air along the equator rises (because of its low density) and cools, allowing water vapor to condense, which results in rainfall, causing precipitation to exceed evaporation in equatorial regions.
3...The Earth is rotating around an axis (called its rotational axis). Some objects rotate about a horizontal axis, like a rolling log. Some objects, such as a skater, rotate about a vertical axis. The Earth's axis is tipped over about 23.5° from vertical
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