When the Earth Moves

For the most part we have all felt an earthquake. Okay so maybe that is an inaccurate assumption, but for those of us who have felt one or been through a significant quake there is this amazing feeling of complete and total loss of control. This isn't just a wind/rain/snow storm you can take shelter from, as a matter of fact taking shelter might be the worst thing to do. Anyway, my thoughts are on Earthquakes because I was woken by one this morning. At least I thought I was. Around 3am something woke me up. A kind of feeling similar to the sensation of riding over a hump on a roller coaster, or when on a swing as you start to swing back with the added moment of fear like when the elevator you are in reaches the bottom floor then kind of "bumps" or "jumps" moving just an inch or so. That was the feeling that woke me up from my dream of being a Superhero (I was the Green Lantern.). I was kind of excited to feel the shaking, but there was nothing. I was actually bummed, not to mention wide awake. I lay there for a moment waiting for aftershocks, or at least the secondary waves of the quake, thinking thoughts about collapsing buildings and destruction, typical 3 am thoughts, but nothing happened. (Must have been the stale nachos I ate at 11pm.) I made a mental note to check the USGS website for the most recent quakes when I get up.............then I finally fell back to sleep. http://earthquake.usgs.gov/earthquakes/recenteqsus/ So this site tells me it was indeed just the nachos, because the last quake in the area was yesterday around Mount Saint Helens, and the latest nearby quake was Nov. 30th, 6 miles SSW(SouthSouthWest) of Sultan. Okay so no quake today, yet. Now for the Earth Science Lesson: Earthquakes are the vibrations sent out by the movement of the Earth's "crust". If you are close enough, and the movement is shallow enough, you experience the movement itself. I think of it similar to being in the center of those cool frozen action photos of a single water drop hitting the surface of the water. The center gets hit and the circumference experiences the waves. The movement we experience is quantified by the Mercalli Scale in a way we can communicate the effects. The actual intensity of the shaking is measured by the Moment magnitude replacing the older Richter Scale. The vibrations are classified, in a simple explanation, into P waves and S waves. P waves are "Primary", or compression waves, causing the up and down motion and that "sick to your stomach" feeling that woke me up. People have described these waves as seeing the pavement ripple up and down. S waves are "Secondary", or shear, waves felt by the side to side shaking. The S waves do the most damage. The waves travel at different speeds through different mediums (rock, sand, water, congealed bacon fat) causing a time lag between them. (The link at the top of this paragraph has a veritable cornucopia of information about quakes.) **************************** Okay the family is waking and I must help with the morning activities.....Later I will post more shots of the house and the NEW WINDOWS that were installed yesterday. Tony