In the beginning, the primeval seas were probably only slightly salty. But over time, as rain fell to the Earth and ran over the land, breaking up rocks and transporting their minerals to the ocean, the ocean has become saltier.
Why is the ocean salty, but rivers flowing into it are not? - 1 views
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Rain replenishes freshwater in rivers and streams, so they don’t taste salty. However, the water in the ocean collects all of the salt and minerals from all of the rivers that flow into i
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It is estimated that the rivers and streams flowing from the United States alone discharge 225 million tons of dissolved solids and 513 million tons of suspended sediment annually to the ocean. Throughout the world, rivers carry an estimated four billion tons of dissolved salts to the ocean annually.
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Why are Oceans Salty? - EnchantedLearning.com - 0 views
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As water flows in rivers, it picks up small amounts of mineral salts from the rocks and soil of the river beds.
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but the salt remains dissolved in the ocean - it does not evaporate. So the remaining water gets saltier and saltier as time passes.
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This very-slightly salty water flows into the oceans and seas. The water in the oceans only leaves by evaporating (and the freezing of polar ice),
Dolphin: Kids Search - powered by EBSCOhost - 0 views
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come in many different shapes and sizes. They can be as small as four feet (1 1/4 meters) long weighing just 100 pounds (45 kilograms), or as large as 30 feet (nine meters) long weighing up to 11,000 pounds (950 kilograms). All dolphins, including even the largest, can move quickly through the water, using paddle-shaped forelimbs called flippers to steer, dorsal fins on their backs to stay balanced, and powerful tail fins called flukes to move forward. Their torpedo-shaped bodies flow smoothly in the water, so they don't make many waves. They use their flippers to make sharp turns and sudden stops. All dolphins have blowholes on the tops of their heads. These mammals breathe through their blowholes. They have to go to the surface of the water to breathe. Each dolphin has just one blowhole.
Blood Flow - HowStuffWorks - 0 views
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All blood enters the right side of the heart through two veins: The superior vena cava (SVC) and the inferior vena cava (IVC) (see figure 3).The SVC collects blood from the upper half of the body. The IVC collects blood from the lower half of the body. Blood leaves the SVC and the IVC and enters the right atrium (RA) (3).When the RA contracts, the blood goes through the tricuspid valve (4) and into the right ventricle (RV) (5). When the RV contracts, blood is pumped through the pulmonary valve (6), into the pulmonary artery (PA) (7) and into the lungs where it picks up oxygen.
Five Stages Of Sleep ... Sleep Cycles Explained - 2 views
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Stage 1This is the lightest stage of sleep, the transition phase, where you feel yourself drifting off. If you were to forget about the alarm clock and allow yourself to wake up naturally, Stage 1 sleep would be the last stage before you fully wake up. You don't spend too much time in Stage 1 sleep, typically five to 10 minutes, just enough to allow your body to slow down and your muscles to relax.
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Stage 2The second stage of sleep is still considered light sleep. Your brain activity starts to slow down, as well as your heart rate and breathing. Your body temperature falls a little and you're beginning to reach a state of total relaxation in preparation for the deeper sleep to come.
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Stage 3Stage 3 sleep is the start of deep sleep, also known as slow wave sleep. During stage 3, your brain waves are slow "delta waves," although there may still be short bursts of faster of brain activity (also known as beta-waves). If you were to get awakened suddenly during this stage, you would be groggy and confused, and find it difficult to focus at first.
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The Purpose of Crying - HowStuffWorks - 0 views
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What happens when you cry, exactly? A salty fluid chock full of protein, water, mucus and oil is released from the lacrimal gland in the upper, outer region of your eye. This fluid, better known as tears, then flows down the surface of your eye, across your face and smears your mascara.
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The reasons for our crying changes as we grow from babies to adults. Learn more on the next page.
The Mariners' Museum | EXPLORATION through the AGES - 0 views
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d. He had brothers, Thorvald and Thorstein, and a half-sister, Freydis. In the year 999 BCE, Ericsson sailed to Norway to visit King Olaf Trygvson. On his way the ship was blown off course and he landed on one of the Hebrides islands. Continuing poor weather made it impossible for him to leave so he spent the summer on the island.
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. She gave birth to his son and as his departure date drew near, she asked that he take her with him. He refused, citing her family connections. Thorgunna had a reputation for being able to predict the future, and vowed that even though Leif was leaving them, one day she and their son would journey to find him and the experience would not be a good one.
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, while other sources claim that when the boy was old enough to travel, he found Leif.
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