The hemoglobin test is often used to check for anemia, usually along with a hematocrit or as part of a complete blood count (CBC) . The test may be used to screen for, diagnose, or monitor a number of conditions and diseases that affect red blood cells (RBCs) and/or the amount of hemoglobin in blood.he hemoglobin test is often used to check for anemia, usually along with a hematocrit or as part of a complete blood count (CBC) . The test may be used to screen for, diagnose, or monitor a number of conditions and diseases that affect red blood cells (RBCs) and/or the amount of hemoglobin in blood.
The volcanoes in this region form a belt called the Ring of Fire. Some of these volcanoes are found in the western United States and Canada. 2. Volcanoes at Divergent Boundaries Volcanoes also form along divergent boundaries where tectonic plates pull apart, allowing magma to rise from the mantle.
Why Volcanoes Occur. Magma is generated in the Earth's lithosphere, which is made up of the crust and upper mantle. (Description of Figure 1.). The roots of Mount St. Helen's are 110 to 330 kilometers (70 to 200 miles) below the Earth's surface.ount St. Helens is typical of more than 80 percent of the volcanoes that have formed on land. Known as subduction zone volcanoes, they occur along the edges of continents where one plate dives, or subducts, beneath a second plate. (fig. 2).