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.
Below: two scenes from the eruption, with just 5 seconds difference. These pictures give a vivid picture of the landslide and eruption that followed 8:32:52:04. Being a composite volcano, Mount St. Helens is formed from âdenserâ lava, called dacite lava. On the day of the eruption of 1980, St. Helens held host to a Phreatic eruption and didnât expel a lava flow of any kind, but it had such an explosive eruption because of its high silica content and high concentration of gas.