## Sunday, 28 October 2012

### Camping in snow? You betcha.....

Who would argue with that point of view?

Camping...rv'ing....running away....oft-times, just about the same thing, in my life. So, in keeping with that topic line...Sharon and I went off for Saturday night. We/I had kind of thought we were going further afield....to a jam session in Kitwanga...but, ultimately, we opted out. It seemed like it was a bit of a cluster-fuck. No one seemed to be answering the phone and on and on and on....

Therefore...instead of a two hour drive, we made it a 20 minute doodle, to what is refrerred to as, Orange Bridge.  It's almost the 1/2 way point between Terrace and Kitimat..has a great camp spot that is heavily used by many. some people seem to spend their entire summer here. They roll in their trailers and 5th wheels and kids and dogs...

Construct tree houses and swinging things.

We got out just about 5:30 and set to making some foody stuff.

First up was a whole steamed artichoke and a whole way too much garlic butter..made the real way. Crushed a whole head of garlic...whooosh.....

I had cooked some chicken earlier in the day...just had to do the pasta, toss in the chicken to heat a bit and chop up a fresh tomato to toss on.

Then it was time to light a fire.....and while I was futzing around outside, Sharon asked me if I was pushing on the rv side. She being kinda rocked side to side..I had said I was playing with the awning, so yeah..I guess. Turns out to have been a earthquake..7.7 on the Richter Scale.

# Richter magnitude scale

The Richter magnitude scale is one of a number of ways that have been developed to assign a single number to quantify the energy contained in an earthquake.
The scale is a base-10 logarithmic scale. The magnitude is defined as the logarithm of the ratio of the amplitude of waves measured by a seismograph to an arbitrary small amplitude. An earthquake that measures 5.0 on the Richter scale has a shaking amplitude 10 times larger than one that measures 4.0, and corresponds to an energy release of √1000 ≈ 31.6 times greater.[1]
Since the mid 20th century, the use of the Richter magnitude scale has largely been supplanted by the moment magnitude scale in many countries. However, the Richter scale is still widely used in Russia and other CIS countries.

## Development

Charles Richter, c. 1970
Developed in 1935 by Charles Richter in partnership with Beno Gutenberg, both from the California Institute of Technology, the scale was firstly intended to be used only in a particular study area in California, and on seismograms recorded on a particular instrument, the Wood-Anderson torsion seismograph. Richter originally reported values to the nearest quarter of a unit, but values were later reported with one decimal place. His motivation for creating the local magnitude scale was to compare the size of different earthquakes.[1] Richter, who since childhood had aspirations in astronomy, drew inspiration from the apparent magnitude scale used to account for the brightness of stars lost due to distance.[2] Richter arbitrarily chose a magnitude 0 event to be an earthquake that would show a maximum combined horizontal displacement of 1 µm (0.00004 in) on a seismogram recorded using a Wood-Anderson torsion seismograph 100 km (62 mi) from the earthquake epicenter. This choice was intended to prevent negative magnitudes from being assigned. The smallest earthquakes that could be recorded and located at the time were around magnitude 3. However, the Richter scale has no lower limit, and sensitive modern seismographs now routinely record quakes with negative magnitudes.
ML (local magnitude) was not designed to be applied to data with distances to the hypocenter of the earthquake greater than 600 km[3] (373 mi). For national and local seismological observatories the standard magnitude scale is today still ML. Unfortunately this scale saturates[clarification needed] at around ML = 6.5, because the high frequency waves recorded locally have wavelengths shorter than the rupture lengths[clarification needed] of large earthquakes.
To express the size of earthquakes around the globe, Gutenberg and Richter later developed a magnitude scale based on surface waves, surface wave magnitude Ms; and another based on body waves, body wave magnitude mb.[4] These are types of waves that are recorded at teleseismic distances. The two scales were adjusted such that they were consistent with the ML scale. This succeeded better with the Ms scale than with the mb scale. Both of these scales saturate when the earthquake is bigger than magnitude 8 and therefore the moment magnitude scale, Mw, was invented.[5]
These older magnitude scales have been superseded by methods for estimating the seismic moment, creating the moment magnitude scale, although the older scales are still widely used because they can be calculated quickly.

## Details

The Richter scale proper was defined in 1935 for particular circumstances and instruments; the instrument used saturated for strong earthquakes. The scale was replaced by the moment magnitude scale (MMS); for earthquakes adequately measured by the Richter scale, numerical values are approximately the same. Although values measured for earthquakes now are actually $M_w$ (MMS), they are frequently reported as Richter values, even for earthquakes of magnitude over 8, where the Richter scale becomes meaningless. Anything above 5 is classified as a risk.[by whom?]
The Richter and MMS scales measure the energy released by an earthquake; another scale, the Mercalli intensity scale, classifies earthquakes by their effects, from detectable by instruments but not noticeable to catastrophic. The energy and effects are not necessarily strongly correlated; a shallow earthquake in a populated area with soil of certain types can be far more intense than a much more energetic deep earthquake in an isolated area.
There are several scales which have historically been described as the "Richter scale," especially the local magnitude $M_L$ and the surface wave $M_s$ scale. In addition, the body wave magnitude, $m_b$, and the moment magnitude, $M_w$, abbreviated MMS, have been widely used for decades, and a couple of new techniques to measure magnitude are in the development stage.
All magnitude scales have been designed to give numerically similar results. This goal has been achieved well for $M_L$, $M_s$, and $M_w$.[6][7] The $m_b$ scale gives somewhat different values than the other scales. The reason for so many different ways to measure the same thing is that at different distances, for different hypocentral depths, and for different earthquake sizes, the amplitudes of different types of elastic waves must be measured.
$M_L$ is the scale used for the majority of earthquakes reported (tens of thousands) by local and regional seismological observatories. For large earthquakes worldwide, the moment magnitude scale is most common, although $M_s$ is also reported frequently.
The seismic moment, $M_o$, is proportional to the area of the rupture times the average slip that took place in the earthquake, thus it measures the physical size of the event. $M_w$ is derived from it empirically as a quantity without units, just a number designed to conform to the $M_s$ scale.[8] A spectral analysis is required to obtain $M_o$, whereas the other magnitudes are derived from a simple measurement of the amplitude of a specifically defined wave.
All scales, except $M_w$, saturate for large earthquakes, meaning they are based on the amplitudes of waves which have a wavelength shorter than the rupture length of the earthquakes. These short waves (high frequency waves) are too short a yardstick to measure the extent of the event. The resulting effective upper limit of measurement for $M_L$ is about 6.5 and about 8 for $M_s$.[9]
New techniques to avoid the saturation problem and to measure magnitudes rapidly for very large earthquakes are being developed. One of these is based on the long period P-wave,[10] the other is based on a recently discovered channel wave.[11]
The energy release of an earthquake,[12] which closely correlates to its destructive power, scales with the 32 power of the shaking amplitude. Thus, a difference in magnitude of 1.0 is equivalent to a factor of 31.6 ($=({10^{1.0}})^{(3/2)}$) in the energy released; a difference in magnitude of 2.0 is equivalent to a factor of 1000 ($=({10^{2.0}})^{(3/2)}$ ) in the energy released.[13] The elastic energy radiated is best derived from an integration of the radiated spectrum, but one can base an estimate on $m_b$ because most energy is carried by the high frequency waves.

## Richter magnitudes

The Richter magnitude of an earthquake is determined from the logarithm of the amplitude of waves recorded by seismographs (adjustments are included to compensate for the variation in the distance between the various seismographs and the epicenter of the earthquake). The original formula is:[14]
$M_\mathrm{L} = \log_{10} A - \log_{10} A_\mathrm{0}(\delta) = \log_{10} [A / A_\mathrm{0}(\delta)],\$
where A is the maximum excursion of the Wood-Anderson seismograph, the empirical function A0 depends only on the epicentral distance of the station, $\delta$. In practice, readings from all observing stations are averaged after adjustment with station-specific corrections to obtain the ML value.
Because of the logarithmic basis of the scale, each whole number increase in magnitude represents a tenfold increase in measured amplitude; in terms of energy, each whole number increase corresponds to an increase of about 31.6 times the amount of energy released, and each increase of 0.2 corresponds to a doubling of the energy released.
Events with magnitudes greater than 4.5 are strong enough to be recorded by a seismograph anywhere in the world, so long as its sensors are not located in the earthquake's shadow.
The following describes the typical effects of earthquakes of various magnitudes near the epicenter. The values are typical only and should be taken with extreme caution, since intensity and thus ground effects depend not only on the magnitude, but also on the distance to the epicenter, the depth of the earthquake's focus beneath the epicenter, the location of the epicenter and geological conditions (certain terrains can amplify seismic signals).
Magnitude Description Average maximum Mercalli intensity Average earthquake effects Average frequency of occurrence (estimated)
Less than 2.0 Micro I to II Microearthquakes, not felt, or felt rarely by sensitive people. Recorded by seismographs.[15] Continual/several million per year
2.0–2.9 Minor I to III Generally felt by few to many people up to several miles/kilometers from the epicenter. Weak shaking in the felt area. Recorded by seismographs. Over one million per year
3.0–3.9 II to V Often felt in the area by at least many people, but very rarely causes damage. Can be felt tens of miles/kilometers from the epicenter. Over 100,000 per year
4.0–4.9 Light III to VII Noticeable shaking of indoor items, rattling noises. Many people, or everyone, feel it with slight to strong intensity. Slightly felt outside. Generally causes none to slight damage. Moderate, heavy, major, or significant damage unlikely. Some falling of objects. 10,000 to 15,000 per year
5.0–5.9 Moderate IV to VIII Can cause moderate to major damage to poorly constructed buildings. At most, slight damage to well-designed buildings. Can be felt hundreds of miles/kilometers from the epicenter at low/lower intensity. It may be reported as very strong to violent intensity tens of miles from the epicenter. 1,000 to 1,500 per year
6.0–6.9 Strong VI to X Can be damaging/destructive in populated areas. Damage to many or all buildings; poorly designed structures incur moderate to severe damage. Earthquake-resistant structures survive with slight to moderate damage. Most likely felt hundreds of miles/kilometers from the epicenter. Death toll between none and more than 25,000. 100 to 150 per year
7.0–7.9 Major VII to XII[16] Can cause great/greater damage over larger areas. Damage to all buildings; many to all receive moderate to very heavy damage, or collapse partially to completely. Death toll is usually between none to more than 150,000. 10 to 20 per year
8.0–8.9 Great VIII to XII Can cause major damage across very wide, large areas. Many to all buildings in epicentral area severely damaged or destroyed. Buildings further from the epicenter will most likely also incur damage. Very strong shaking up to a few hundred miles/kilometers away. Death toll is usually between 50 to more than 500,000, however some earthquakes this magnitude have killed none. One per year (rarely none, two, or over two per year)
9.0–9.9 Destructive to very devastating in extremely large areas. Many to all buildings severely damaged to completely destroyed up to tens of miles from the epicenter. Easily felt and/or damaging at extremely distant points. Ground changes. Death toll usually between 250 and one million. One per 5 to 50 years
10.0+ Massive/Epic IX to XII Heavy, widespread, colossal damage/devastation across enormous areas. Large ground changes. Never recorded; see below for equivalent seismic energy yield. None per year (unknown, extremely rare, or impossible/may not be possible)
(Based on U.S. Geological Survey documents.)[17]
The intensity and death toll can vary a lot because it depends on several factors (earthquake depth, epicenter location, population density, to name a few).
Great earthquakes occur once a year, on average. The largest recorded earthquake was the Great Chilean Earthquake of May 22, 1960, which had a magnitude of 9.5 on the moment magnitude scale.[18]

Fire and Sambucca with your marshmallows, in the snow.

In the morning.....coffee, bacon, boiled eggs.....and some cinnamon/raisin bread fried in the bacon grease. OMG..if you have never had bread fried in bacon drippings....prepare yourselves.....of course, you have to like bacon first...and toast.

Sharon was just waiting.....out of the way and all cuddled up.

Leaving the night spot.

This is maybe the best RV ever...four wheel drive, Triple E Regal.