crater formation

crater formation

A popular term for a circular depression of skin or mucosa overlying a circumscribed focus of necrosis; the finding has also been described in the gingiva overlying periodontal disease.
References in periodicals archive ?
During the modification stage of crater formation, the uplift of the central peak and surrounding floor would create a crater infill of low-density highlands rocks fractured by the impact event.
Surface morphology of platinum indicates the crater formation due to intense beam and particles splashed out in outward direction from ablated part of the material (figure 1c).
In Figure 4 (a), ion induced chains and crater formation were shown irradiated at 100 V, at magnification of 100.
Numerical simulations of crater formation on Mars (Senft and Stewart 2008) suggests that variations in morphometry of shallow craters may be explained by modification of crater excavation and collapse processes by the presence of ice overlying target rock.
In general, calculations involving the crater size will provide only a minimum energy of crater formation. Various formulae have been published which relate the size of a crater to the impact parameters.
Damage crater formation is similar to crater formation due to meteorite impact or to underground explosion [53, 54].
The pressure-implicit with splitting of operators (PISO) pressure-velocity coupling scheme was used to calculate the transient two-phase fluid flow, and the iterative time step is set to [10.sup.-6] S to ensure the accurate results of crater formation.
Water does not cause craters by itself, but can be a carrier for any oil in the system, thereby aiding in crater formation, usually on an irregular basis.
Indeed, if we leave aside Robert Hooke's 'bubble' theory of crater formation a century or so earlier, Herschel might well be regarded as the first 'British' selenographer to argue for a volcanic theory of crater formation--a view that, as we shall see, came to dominate and shape nearly all later British thinking about the nature of the Moon.
Because the procedure to determine the rates of crater formation has been previously described (Kauffman 2011; Kauffman and Wolf 2012), an example of the weight loss (measured with an analytical balance) versus exposure time plots is shown in Figure 2 for polystyrene foam exposed to 1000-11,000 [micro]W/c[m.sup.2] irradiance (Figure 1) for up to 2000 hours.
This information will help researchers understand crater formation and study other uncharted areas of the moon.
Use this "Create a Crater" Hands-On skills sheet from the online database at www.scholastic.com/scienceworld to have your students simulate a volcanic eruption and crater formation.