Impact excitation of a seismic pulse and vibrational normal modes on asteroid Bennu and associated slumping of regolith

doi:10.1016/j.icarus.2018.09.032

	Impact excitation of a seismic pulse and vibrational normal modes on asteroid Bennu and associated slumping of regolith
	Quillen, Alice C.1; Zhao, Yuhui2 ; Che, Yuanyuan 2; Sanchez, Paul 3; Nelson, Randal C.4; Schwartz, Stephen R.5,6
刊名	ICARUS
	2019-02-01
卷号	319 页码:312-333
关键词	Asteroids Surfaces - asteroids Individual Bennu - impact processes
ISSN号	0019-1035
DOI	10.1016/j.icarus.2018.09.032
通讯作者	Quillen, Alice C.(alice.quillen@rochester.edu)
英文摘要	We consider an impact on an asteroid that is energetic enough to cause resurfacing by seismic reverberation and just below the catastrophic disruption threshold, assuming that seismic waves are not rapidly attenuated. In asteroids with diameter less than 1 km we identify a regime where rare energetic impactors can excite seismic waves with frequencies near those of the asteroid's slowest normal modes. In this regime, the distribution of seismic reverberation is not evenly distributed across the body surface. With mass-spring model elastic simulations, we model impact excitation of seismic waves with a force pulse exerted on the surface and using three different asteroid shape models. The simulations exhibit antipodal focusing and normal mode excitation. If the impulse excited vibrational energy is long lasting, vibrations are highest at impact point, its antipode and at high surface elevations such as an equatorial ridge. A near equatorial impact launches a seismic impulse on a non spherical body that can be focused on two additional points on an the equatorial ridge. We explore simple flow models for the morphology of vibration induced surface slumping. We find that the initial seismic pulse is unlikely to cause large shape changes. Long lasting seismic reverberation on Bennu caused by a near equatorial impact could have raised the height of its equatorial ridge by a few meters and raised two peaks on it, one near impact site and the other near its antipode.
WOS关键词	NUMERICAL SIMULATIONS ; GRANULAR MATERIAL ; WAVE PROPAGATION ; PONDED DEPOSITS ; FLOWS ; FLUIDIZATION ; EVOLUTION ; MOTION ; MASS ; DISRUPTIONS
WOS研究方向	Astronomy & Astrophysics
语种	英语
出版者	ACADEMIC PRESS INC ELSEVIER SCIENCE
WOS记录号	WOS:000455422800018
内容类型	期刊论文
源URL	[http://libir.pmo.ac.cn/handle/332002/19185]
专题	中国科学院紫金山天文台
通讯作者	Quillen, Alice C.
作者单位	1.Univ Rochester, Dept Phys & Astron, Rochester, NY 14627 USA 2.Chinese Acad Sci, Purple Mt Observ, Key Lab Planetary Sci, Nanjing 210008, Jiangsu, Peoples R China 3.Univ Colorado, Colorado Ctr Astrodynam Res, UCB 431, Boulder, CO 80309 USA 4.Univ Rochester, Dept Comp Sci, Rochester, NY 14627 USA 5.Univ Arizona, Lunar & Planetary Lab, Tucson, AZ 85721 USA 6.Univ Cote dAzur, Lab Lagrange, Observ Cote dAzur, CNRS, CS 34229, F-06304 Nice 4, France
推荐引用方式 GB/T 7714	Quillen, Alice C.,Zhao, Yuhui,Che, Yuanyuan,et al. Impact excitation of a seismic pulse and vibrational normal modes on asteroid Bennu and associated slumping of regolith[J]. ICARUS,2019,319:312-333.
APA	Quillen, Alice C.,Zhao, Yuhui,Che, Yuanyuan,Sanchez, Paul,Nelson, Randal C.,&Schwartz, Stephen R..(2019).Impact excitation of a seismic pulse and vibrational normal modes on asteroid Bennu and associated slumping of regolith.ICARUS,319,312-333.
MLA	Quillen, Alice C.,et al."Impact excitation of a seismic pulse and vibrational normal modes on asteroid Bennu and associated slumping of regolith".ICARUS 319(2019):312-333.