There are four important warning signs that should prompt you to talk to a health care provider. 1  Pain. Pain from arthritis can be constant or it may come and go. 2  Swelling. Some types of arthritis cause the skin over the affected joint to become red and swollen, feeling warm to the touch. 3  Stiffness.
There's a whole lot of water on Earth! Something like 326,000,000,000,000,000,000 gallons (326 million trillion gallons) of the stuff (roughly 1,260,000,000,000,000,000,000 liters) can be found on our planet. This water is in a constant cycle -- it evaporates from the ocean, travels through the air, rains down on the land and then flows back to the ocean.
The volume of water in the oceans is enormous: 1.37 billion cubic kilometers (1.37 Ã 10 9 km 3, or 0.328 Ã 10 9 mi. 3). 1.37 Ã 10 9 km 3. Ocean and Oceanography. Microsoft Encarta. The world ocean covers 71 percent of the earth's surface, or about 361 million sq km (140 million sq mi). Its average depth is 5,000 m (16,000 ft), and its total volume is about 1,347,000,000 cu km (322,300,000 cu mi)..