Craters

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If craters are formed by the impact of Meteorites then how are these impact craters formed? One is a crater chain and the other looks like Mickey Mouse with hoop earing!




What if an idea can explain these and other craters. With an explaination that is used by engineers, on a smaller scale, every day?

The interior morphology of impact craters becomes more complicated with increasing crater size. However, this size/morphology relationship is not continuous, but shows marked transitions. The two most important discontinuities are the transition between simple and complex craters, and between large craters and small basins.

It is believed that these morphological differences are not a direct result of the crater excavation process, but develop after most of the material has been expelled from the crater.

The initial product of an impact is thought to be a circular, bowl-shaped cavity with a depth to diameter ratio between 1:4 and 1:3. The shape of this initial crater is independent of its diameter, the impact velocity, impact angle (except for very small angles), gravitational acceleration, and the properties of the target and impactor. This “transient” crater is subsequently modified by gravitational collapse, giving rise to a final morphology which is determined by the conditions of the target site.

Crater collapse depends on the stength of the material surrounding the crater, which is shattered, heated and shaken by the impact. However, if these rocks retained their static strength properties, impact craters would not collapse at all. This indicates some rock weakening processes must be active during crater formation, resulting in a much lower dynamic strenth of the material; acoustic fluidisation and shock weakening have been proposed as possible mechanisms.
OUGS Mainland Europe

Impact craters on the moon? or to quote someone "Do you think that is air you are breathing now?"[/size]



What if an idea about how craters were formed may also explain the puzzling Transient Lunar Phenomenon that until a few years ago was thought of as a Lunatic idea.

• Craters have distinct categories/characteristics depending on their size. If meteorites are very different in size. speed, angle. material, age when they hit the moon or the earth (also both meant to be very different depending on when the meteorite struck) how can they always seem to create the same type of crater according to the size of the crater?
• A lot of the changes or shaping of the crater occurs after the impact.

• "acoustic fluidisation and shock weakening" - frequency and shock waves - electrical/plasma events create frequencies and shock waves - think of tornados, lightning and thunder, the Sun etc.

The material around and in the craters has been transformed by the application of a lot of energy. How or where that energy comes from is still open to debate. Impact craters formation is still only a theory. What if there was another explanation that provides all the same ingredients of energy, shockwaves and is used everyday by engineers?

Craters may have been formed by an EDM / Spark Machining / Plasma Discharge Event. Have a look for yourself. Why do all craters look like they were hit directly from above?

http://www.youtube.com/watch?v=3rqQnUCiWQo - youtube - Crater formation shown in experiment
http://www.youtube.com/watch?v=WB_EKVWgbj8 - youtube - Electrical crater formation shown in experiment
http://www.youtube.com/watch?v=NaJ3OanxiW8 - youtube - Crater formation shown on youtube

Links
Bahrija Crater, Malta - Crater or doline?

more Electric Universe geology sites
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Simple craters

Simple craters are circular, bowl-shaped depressions with elevated rims and an approximately parabolic interior profile. They have no major internal topographic features.

One of the most important characteristics of impact craters is their ratio of rim-to-floor depth to the rim-to-rim diameter (d/D), which has a value of about 1:5 for most simple craters on the terrestrial planets as well as on the Moon. The upper rim of a simple crater often shows stratification and evidence of mass-wasting. Most lunar craters smaller than about 15 km in diameter are simple, while on Earth the upper limit is about 4 km.

The floor of simple craters is underlain by a breccia lens consisting of rock debris and shock-melted rock with a thickness of about half the rim-to-floor depth of the crater. This lens in turn lies in a bowl of fractured country rock. It is thought that the final shape of a simple crater is formed mainly by the gravitational collapse of the rim of the transient crater immediately after it forms.
OUGS

• It appears that the actual Meteorite has little to do with physical properties of the crater
• Interestingly the ratios appear to be the same value for the Earth as well as the moon
• The gravity on the moon is a lot less than the earths but still it helps create the same type of crater, after the impact

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Complex craters

Complex craters range in diameter from a few kilometers on Earth to a huge 460 km diameter crater observed on asteroid 4 Vesta. The 15 Ma Ries crater in Bavaria, which was visited during the last AGM in Munich, is one of the best known middle-sized complex craters on Earth, with a diameter of about 24 km.

Complex craters have a d/D ratio which varies widely fom 1:5 for small fresh complex craters to 1:150 for large craters, depending upon the planet. On Earth they exhibit central stuctural uplifts, rim synclines, and outer concentric zones of normal faulting. Extraterrestrial craters have been observed with multiple central peaks and terraced rims. The central uplift consists of strata which have been uplifted above the pre-impact level, and is surrounded by a ring depression (or rim syncline) filled with fragmented material and impact melt. The uplift of the transient cavity’s floor — accompanied by subsidence of the crater rim — is thought to be the main modification mechanism for complex craters.

The transition between simple and complex craters occurs over a narrow diameter range on a particular solar system body and is thought to scale as the inverse power of the surface gravity, g. The transition occurs around 15 km diameter on the Moon, 7 km on Mars and about 4 km on Earth. As the crater size increases further, the central peak complex in a complex crater begins to break up and form an inner ring of mountains. In large craters the ring is about half the rim-to-rim diameter, and these craters are called “peak-ring” craters.

However, not all of the complex crater features appear at the same diameter. Therefore the transition diameter is often expressed as the geometric mean, Dt, of several diameter values at which particular morphological features, such as central uplifts and terraced walls, appear. Studies on Martian craters indicate that the first complex features to appear are a flat floor, a central peak and a low d/D ratio.

Interestingly, the Dt values for Earth (3.1 km) and the Moon (18.7 km) differ by a factor of six, which is exactly the ratio of their values of g. In addition, complex craters on the Moon are on average six times deeper than on Earth.

Despite the importance of gravity, the lithology of the target area influences the value of Dt as well. This is best established for terrestrial craters of course, giving a simple-to-complex crater transition diameter of 2.25 km for sedimentary rocks and 4.75 km for crystalline rocks. It is thought that at least three (interrelated) target properties influence the shape of the final crater: rock strength, stratification and volatile content. An impact of a given energy will excavate a larger cavity in soft rocks, while there is evidence that complex craters develop more readily in stratified rocks.

The simple-to-complex transition coincides with a change in the texture of the ejecta surrounding fresh martian impact craters (this is of course more difficult to observe on Earth), indicating the mechanism of ejecta emplacement is dependent on crater size.

Craters less than 4 km in diameter show typical ballistic ejecta characteristics, while between 4 and 80 km emplacement seems to occur at least partly by surface flow, and larger craters again have ballistic ejecta emplacement. This might be explained by the incorporation of subsurface volatiles in the ejecta for impacts of intermediate size, while small impacts do not excavate deep enough to tap these volatiles, and large impacts completely vaporise them.
OUGS

• Gravity seems to be the most importantant factor - was there ever an actual Meteorite or did something else cause it that was influenced by gravity?
• If Gravity is an Electric Universe force then the importance of "G" to the creation of craters shapes makes more sense.
• Transient lunar phenomenon may be the clue to what has and could still happen.  If craters are formed by EDM this would account for the "G" ratio. It would also account for TLPs, they are a plasma/electric discharge happening on the moon.

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Multi-ring basins

The largest impact craters form small basins containing a series of multiple concentric ridges, and they seem to come in two basic types. The classic basin is Orientale on the Moon, which features at least five circular rings that form inward-facing scarps up to 6 km high. The second type is the Valhalla structure on the Jovian moon Callisto. This multi-ring basin consists of a bright central patch surrounded by a system of concentric ridges. These ridges are surrounded by dozens of grabens that may extend thousands of kilometers from the impact point. On Earth, the 65 Ma, 180 km diameter Chicxulub crater in Mexico is one of the few examples positively identified as a multi-ring basin. These basins are thought to form as a tectonic response of the target’s lithosphere the the crater formed by the impact, and indicates the presence of a low-viscosity or low-strength layer below the surface. The transition between peak or peak ring craters and rimmed basins on different bodies does not relate to the surface gravity of the body, but seems to depend a great deal on the rheological properties near the surface, in particular the presence of a weak subsurface layer which can flow on the timescale of the crater collapse. However, the formation of these basins is still not very well understood.
OUGS
 

Ridges and concentric rings - how are these formed? Scientists always use the "water drop and ripples" to explain it but a meteorite hitting a planet is not a drop of fluid hitting more fluid.  These Meteorites are meant to be of varied material (remember the dirty snow ball idea?) hitting at different speeds at different times of the planets history yet make similar impacts...
Maybe what created all the craters is the same force and that is why the actual planet has little to do with the result. The planet will effect it but mainly with its "G".

If it was an EDM (Spark Machining) event then that would help to explain crater chains.

And if it created craters then what else would a very large electrical spark create?

The earth as a lightning strike victim (The Grand Canyon) and also a human struck by a lightning bolt

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strange craters - impacts, volcanic or spark machined (EDM)?



Is this a volcanic crater cone or an "impact crater"?

If its a a volcanic cone then is the whole island made of the same volcanic material and why is the cone on the edge?

If it is an impact crater then why is it so small, why is the bottom so flat and what are the odds that it would be found on the edge of the island (rim shot craters)?