Related Experiment Video
Updated: Feb 3, 2026
07:26
Formation of Ordered Biomolecular Structures by the Self-assembly of Short Peptides
Published on: November 21, 2013
13.4K
Rock fluidization during peak-ring formation of large impact structures.
Ulrich Riller1, Michael H Poelchau2, Auriol S P Rae3
1Institut für Geologie, Universität Hamburg, Hamburg, Germany. ulrich.riller@uni-hamburg.de.
Nature
|October 26, 2018
Summary
Meteorite impacts cause rocks to drastically weaken, flow, and then regain strength to form impact rings. This study reveals acoustic fluidization as a key process in cratering mechanics.
Area of Science:
- Planetary Science
- Geology
- Impact Cratering
Background:
- Terrestrial impact structures exhibit prominent topographic rings formed by uplifted crustal rocks.
- The rapid deformation and subsequent strength recovery of these rocks during cratering remain poorly understood.
Purpose of the Study:
- To investigate the mechanisms of rock deformation responsible for the formation of impact crater rings.
- To elucidate the processes of catastrophic weakening and strength recovery in target rocks during large impacts.
Main Methods:
- Analysis of core samples from the Chicxulub impact structure.
- Examination of brittle and viscous deformation within peak-ring rocks.
Main Results:
- Observed catastrophic rock weakening followed by strength increase during cratering.
- Evidence suggests acoustic fluidization as the dominant initial cratering process.
- Subsequent crater formation involved increasingly localized faulting.
Conclusions:
- Acoustic fluidization explains the initial rapid flow and large-scale deformation of target rocks.
- The transition from fluidization to localized faulting explains the formation and sustainment of topographic rings in impact structures.
Related Concept Videos
01:19Impact of Groups on Groups
249
Social psychologists analyze how groups influence one another, shaping social structures and interactions through both cooperation and competition. These dynamics manifest in various ways, ranging from economic partnerships to intergroup conflicts that shape societal structures and perceptions.Cooperation and Competition in Intergroup RelationsIntergroup relationships vary across contexts, sometimes fostering cooperation and mutual benefit while at other times leading to conflict and...
249
01:08IR Spectrum Peak Splitting: Symmetric vs Asymmetric Vibrations
1.8K
Identical bonds within a polyatomic group can stretch symmetrically (in-phase) or asymmetrically (out-of-phase). Similar to hydrogen bonding, these vibrations also influence the shape of the IR peak. Generally, asymmetric stretching frequencies are higher than symmetric stretching frequencies. For example, primary amines exhibit two distinct IR peaks between 3300–3500 cm−1 corresponding to the symmetric and asymmetric N-H stretching, while secondary amines exhibit a single...
1.8K
00:55IR Spectrum Peak Intensity: Amount of IR-Active Bonds
1.1K
When infrared radiation is passed through a molecule, absorption occurs if the molecule's vibration leads to a substantial change in its bond dipole moment. Transitions between vibrational energy levels, typically corresponding to infrared frequencies (4000–400 cm−1), allow absorption if the vibration significantly alters the dipole moment, making the molecule infrared active. The molecular bonds have different stretching and bending vibrations, resulting in various peaks with...
1.1K
01:23IR Spectrum Peak Broadening: Hydrogen Bonding
1.8K
The vibrational frequency of a bond is directly proportional to its bond strength. As a result, stronger bonds vibrate at higher frequencies, while weaker bonds vibrate at lower frequencies. The stretching vibration of the strong O–H bond in alcohols and phenols (very dilute solution or gas phase) appears as a sharp peak at 3600–3650 cm−1.
However, the extent of hydrogen bonding influences the observed stretching frequency and band broadening. Intermolecular or intramolecular...
However, the extent of hydrogen bonding influences the observed stretching frequency and band broadening. Intermolecular or intramolecular...
1.8K
01:20IR Spectrum Peak Intensity: Dipole Moment
1.5K
The dipole moment of a bond is the product of the partial charge on either atom and the distance between them. Dipole moments influence the efficiency of IR absorption and the peak intensity. When a bond with a dipole moment is placed in an electric field, the direction of the field determines if the bond is compressed or stretched. Electromagnetic radiation consists of an electric field component that rapidly reverses direction. It follows that polar bonds are alternately stretched and...
1.5K
01:30Impact
499
Impact occurs when two bodies collide, leading to the application of impulsive forces between them. Analyzing impact mechanics involves considering two colliding particles moving along a line known as the line of impact, which passes through their centers and is perpendicular to the contact plane.
When particles with different initial velocities collide, they induce deformation by applying equal and opposite impulses. At the point of maximum deformation, the particles move together with...
When particles with different initial velocities collide, they induce deformation by applying equal and opposite impulses. At the point of maximum deformation, the particles move together with...
499