The yarn number is the length in yards of one pound of the yarn, divided by 1600. Symbol Nar. This is the same as the weight in ounces of 100 yards. So one pound of number 1 run yarn is 1600 yards long, one pound of number 2 run yarn is 3200 yards long, and so on.
As with most other volcanoes in the Cascade Range, Mount St. Helens is a large eruptive cone consisting of lava rock interlayered with ash, pumice, and other deposits. The mountain includes layers of basalt and andesite through which several domes of dacite lava have erupted.
Stratovolcanoes tend to have many vents including cinder cones and domes found low on all sides of the volcano. Classifying the Three Main Types of Volcanoes explains volcanic types in detail. Tectonic Plates. Mt. Fuji sits on a subduction zone of tectonic plates where the Philippine plate is sinking beneath Japan. A tear in the Philippine plate was discovered by scientists at the University of Kyoto, allowing high volumes of mantle to keep Mt. Fujiâs magma chamber filled.