Imperial College London

Professor Gareth Collins

Faculty of EngineeringDepartment of Earth Science & Engineering

Professor of Planetary Science
 
 
 
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Contact

 

+44 (0)20 7594 1518g.collins Website

 
 
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Location

 

4.83Royal School of MinesSouth Kensington Campus

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Summary

 

Publications

Publication Type
Year
to

130 results found

Raducan SD, Davison TM, Luther R, Collins GSet al., 2019, The role of asteroid strength, porosity and internal friction in impact momentum transfer, Icarus, Vol: 329, Pages: 282-295, ISSN: 0019-1035

© 2019 Elsevier Inc. Earth is continually impacted by very small asteroids and debris, and a larger object, though uncommon, could produce a severe natural hazard. During impact crater formation the ballistic ejection of material out of the crater is a major process, which holds significance for an impact study into the deflection of asteroids. In this study we numerically simulate impacts into low-gravity, strength dominated asteroid surfaces using the iSALE shock physics code, and consider the Double Asteroid Redirection Test (DART)mission as a case study. We find that target cohesion, initial porosity, and internal friction coefficient greatly influence ejecta mass/velocity/launch-position distributions and hence the amount by which an asteroid can be deflected. Our results show that as the cohesion is decreased the ratio of ejected momentum to impactor momentum, β − 1, increases; β − 1 also increases as the initial porosity and internal friction coefficient of the asteroid surface decrease. Using nominal impactor parameters and reasonable estimates for the material properties of the Didymos binary asteroid, the DART target, our simulations show that the ejecta produced from the impact can enhance the deflection by a factor of 2 to 4. We use numerical impact simulations that replicate conditions in several laboratory experiments to demonstrate that our approach to quantify ejecta properties is consistent with impact experiments in analogous materials. Finally, we investigate the self-consistency between the crater size and ejection speed scaling relationships previously derived from the point-source approximation for impacts into the same target material.

JOURNAL ARTICLE

McMullan S, Collins GS, 2019, Uncertainty quantification in continuous fragmentation airburst models, ICARUS, Vol: 327, Pages: 19-35, ISSN: 0019-1035

JOURNAL ARTICLE

Lyons RJ, Bowling TJ, Ciesla FJ, Davison TM, Collins GSet al., The effects of impacts on the cooling rates of iron meteorites, Meteoritics & Planetary Science, ISSN: 1086-9379

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Derrick JG, Rutherford ME, Chapman DJ, Davison TM, Duarte JPP, Farbaniec L, Bland PA, Eakins DE, Collins GSet al., 2019, Investigating shock processes in bimodal powder compaction through modelling and experiment at the mesoscale, INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES, Vol: 163, Pages: 211-219, ISSN: 0020-7683

JOURNAL ARTICLE

Bellucci JJ, Nemchin AA, Grange M, Robinson KL, Collins G, Whitehouse MJ, Snape JF, Norman MD, Kring DAet al., 2019, Terrestrial-like zircon in a clast from an Apollo 14 breccia, Earth and Planetary Science Letters, Vol: 510, Pages: 173-185, ISSN: 0012-821X

© 2019 Elsevier B.V. A felsite clast in lunar breccia Apollo sample 14321, which has been interpreted as Imbrium ejecta, has petrographic and chemical features that are consistent with formation conditions commonly assigned to both lunar and terrestrial environments. A simple model of Imbrium impact ejecta presented here indicates a pre-impact depth of 30–70 km, i.e. near the base of the lunar crust. Results from Secondary Ion Mass Spectrometry trace element analyses indicate that zircon grains recovered from this clast have positive Ce/Ce ⁎ anomalies corresponding to an oxygen fugacity +2 to +4 log units higher than that of the lunar mantle, with crystallization temperatures of 771±88 to 810 ± 37 °C (2σ) that are unusually low for lunar magmas. Additionally, Ti-in-quartz and zircon calculations indicate a pressure of crystallization of 6.9±1.2 kbar, corresponding to a depth of crystallization of 167±27 km on the Moon, contradicting ejecta modelling results. Such low-T, high-fO 2 , and high-P have not been observed for any other lunar clasts, are not known to exist on the Moon, and are broadly similar to those found in terrestrial magmas. The terrestrial-like redox conditions inferred for the parental magma of these zircon grains and other accessory minerals in the felsite contrasts with the presence of Fe-metal, bulk clast geochemistry, and the Pb isotope composition of K-feldspar grains within the clast, all of which are consistent with a lunar origin. The dichotomy between redox conditions and the depth of origin inferred from the zircon compositions compared to the ejecta modelling necessitates a multi-stage petrogenesis. Two, currently unresolvable hypotheses for the origin and history of the clast are allowed by these data. The first postulates that the relatively oxidizing conditions were developed in a lunar magma, possibly by fractional crystallization and enrichment of incompatible elements in a fluid-rich

JOURNAL ARTICLE

Urrutia-Fucugauchi J, Pérez-Cruz L, Morgan J, Gulick S, Wittmann A, Lofi J, Morgan JV, Gulick SPS, Chenot E, Christeson G, Claeys P, Cockell C, Coolen MJL, Ferrière L, Gebhardt C, Goto K, Jones H, Kring DA, Lofi J, Lowery C, Mellett C, Ocampo-Torres R, Pickersgill A, Poelchau M, Rae A, Rasmussen C, Rebolledo-Vieyra M, Riller U, Sato H, Smit J, Tikoo-Schantz S, Tomioka N, Whalen M, Xiao L, Yamaguchi KE, Bralower T, Collins GSet al., 2019, Peering inside the peak ring of the Chicxulub Impact Crater—its nature and formation mechanism, Geology Today, Vol: 35, Pages: 68-72, ISSN: 0266-6979

© 2019 John Wiley & Sons Ltd, The Geologists' Association & The Geological Society of London The IODP-ICDP Expedition 364 drilled into the Chicxulub crater, peering inside its well-preserved peak ring. The borehole penetrated a sequence of post-impact carbonates and a unit of suevites and clast-poor impact melt rock at the top of the peak ring. Beneath this sequence, basement rocks cut by pre-impact and impact dykes, with breccias and melt, were encountered at shallow depths. The basement rocks are fractured, shocked and uplifted, consistent with dynamic collapse, uplift and long-distance transport of weakened material during collapse of the transient cavity and final crater formation.

JOURNAL ARTICLE

Hopkins RT, Osinski GR, Collins GS, 2019, Formation of Complex Craters in Layered Targets With Material Anisotropy, JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS, Vol: 124, Pages: 349-373, ISSN: 2169-9097

JOURNAL ARTICLE

Rae ASP, Collins GS, Poelchau M, Riller U, Davison TM, Grieve RAF, Osinski GR, Morgan JV, Gulick SPS, Morgan JV, Chenot E, Christeson GL, Claeys P, Cockell CS, Coolen MJL, Ferriere L, Gebhardt C, Goto K, Green S, Jones H, Kring DA, Lofi J, Lowery CM, Ocampo-Torres R, Perez-Cruz L, Pickersgill AE, Poelchau M, Rae ASP, Rasmussen C, Rebolledo-Vieyra M, Riller U, Sato H, Smit J, Tikoo SM, Tomioka N, Urrutia-Fucugauchi J, Whalen MT, Wittmann A, Xiao L, Yamaguchi KEet al., 2019, Stress-Strain Evolution During Peak-Ring Formation: A Case Study of the Chicxulub Impact Structure, JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS, Vol: 124, Pages: 396-417, ISSN: 2169-9097

JOURNAL ARTICLE

Rutherford ME, Derrick JG, Chapman DJ, Collins GS, Eakins DEet al., 2019, Insights into local shockwave behavior and thermodynamics in granular materials from tomography-initialized mesoscale simulations, JOURNAL OF APPLIED PHYSICS, Vol: 125, ISSN: 0021-8979

JOURNAL ARTICLE

Daubar I, Lognonné P, Teanby NA, Miljkovic K, Stevanović J, Vaubaillon J, Kenda B, Kawamura T, Clinton J, Lucas A, Drilleau M, Yana C, Collins GS, Banfield D, Golombek M, Kedar S, Schmerr N, Garcia R, Rodriguez S, Gudkova T, May S, Banks M, Maki J, Sansom E, Karakostas F, Panning M, Fuji N, Wookey J, van Driel M, Lemmon M, Ansan V, Böse M, Stähler S, Kanamori H, Richardson J, Smrekar S, Banerdt WBet al., 2018, Impact-seismic investigations of the InSight mission, Space Science Reviews, Vol: 214, ISSN: 0038-6308

Impact investigations will be an important aspect of the InSight mission. One of the scientific goals of the mission is a measurement of the current impact rate at Mars. Impacts will additionally inform the major goal of investigating the interior structure of Mars. In this paper, we review the current state of knowledge about seismic signals from impacts on the Earth, Moon, and laboratory experiments. We describe the generalized physical models that can be used to explain these signals. A discussion of the appropriate source time function for impacts is presented, along with spectral characteristics including the cutoff frequency and its dependence on impact momentum. Estimates of the seismic efficiency (ratio between seismic and impact energies) vary widely. Our preferred value for the seismic efficiency at Mars is 5 × 10 − 4, which we recommend using until we can measure it during the InSight mission, when seismic moments are not used directly. Effects of the material properties at the impact point and at the seismometer location are considered. We also discuss the processes by which airbursts and acoustic waves emanate from bolides, and the feasibility of detecting such signals. We then consider the case of impacts on Mars. A review is given of the current knowledge of present-day cratering on Mars: the current impact rate, characteristics of those impactors such as velocity and directions, and the morphologies of the craters those impactors create. Several methods of scaling crater size to impact energy are presented. The Martian atmosphere, although thin, will cause fragmentation of impactors, with implications for the resulting seismic signals. We also benchmark several different seismic modeling codes to be used in analysis of impact detections, and those codes are used to explore the seismic amplitude of impact-induced signals as a function of distance from the impact site. We predict a measurement of the current impact flux will be possibl

JOURNAL ARTICLE

Johnson BC, Andrews-Hanna JC, Collins GS, Freed AM, Melosh HJ, Zuber MTet al., 2018, Controls on the Formation of Lunar Multiring Basins, JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS, Vol: 123, Pages: 3035-3050, ISSN: 2169-9097

JOURNAL ARTICLE

Riller U, Poelchau MH, Rae ASP, Schulte FM, Collins GS, Melosh HJ, Grieve RAF, Morgan JV, Gulick SPS, Lofi J, Diaw A, McCall N, Kring DAet al., 2018, Rock fluidization during peak-ring formation of large impact structures, NATURE, Vol: 562, Pages: 511-+, ISSN: 0028-0836

JOURNAL ARTICLE

Luther R, Zhu M-H, Collins G, Wuennemann Ket al., 2018, Effect of target properties and impact velocity on ejection dynamics and ejecta deposition, METEORITICS & PLANETARY SCIENCE, Vol: 53, Pages: 1705-1732, ISSN: 1086-9379

JOURNAL ARTICLE

Collins GS, Rae ASP, Morgan JV, Gulick Set al., 2018, THE FORMATION OF PEAK RINGS IN LARGE IMPACT CRATERS, 81st Annual Meeting of the Meteoritical-Society, Publisher: WILEY, Pages: 6215-6215, ISSN: 1086-9379

CONFERENCE PAPER

Derrick JG, LaJeunesse JW, Davison TM, Borg JP, Collins GSet al., 2018, Mesoscale simulations of shock compaction of a granular ceramic: effects of mesostructure and mixed-cell strength treatment, MODELLING AND SIMULATION IN MATERIALS SCIENCE AND ENGINEERING, Vol: 26, ISSN: 0965-0393

JOURNAL ARTICLE

Brooker LM, Balme MR, Conway SJ, Hagermann A, Barrett AM, Collins GS, Soare RJet al., 2018, Clastic polygonal networks around Lyot crater, Mars: Possible formation mechanisms from morphometric analysis, Icarus, Vol: 302, Pages: 386-406, ISSN: 0019-1035

© 2017 The Authors Polygonal networks of patterned ground are a common feature in cold-climate environments. They can form through the thermal contraction of ice-cemented sediment (i.e. formed from fractures), or the freezing and thawing of ground ice (i.e. formed by patterns of clasts, or ground deformation). The characteristics of these landforms provide information about environmental conditions. Analogous polygonal forms have been observed on Mars leading to inferences about environmental conditions. We have identified clastic polygonal features located around Lyot crater, Mars (50°N, 30°E). These polygons are unusually large (>100 m diameter) compared to terrestrial clastic polygons, and contain very large clasts, some of which are up to 15 metres in diameter. The polygons are distributed in a wide arc around the eastern side of Lyot crater, at a consistent distance from the crater rim. Using high-resolution imaging data, we digitised these features to extract morphological information. These data are compared to existing terrestrial and Martian polygon data to look for similarities and differences and to inform hypotheses concerning possible formation mechanisms. Our results show the clastic polygons do not have any morphometric features that indicate they are similar to terrestrial sorted, clastic polygons formed by freeze-thaw processes. They are too large, do not show the expected variation in form with slope, and have clasts that do not scale in size with polygon diameter. However, the clastic networks are similar in network morphology to thermal contraction cracks, and there is a potential direct Martian analogue in a sub-type of thermal contraction polygons located in Utopia Planitia. Based upon our observations, we reject the hypothesis that polygons located around Lyot formed as freeze-thaw polygons and instead an alternative mechanism is put forward: they result from the infilling of earlier thermal contraction cracks by wind-blown mat

JOURNAL ARTICLE

Derrick JG, Rutherford ME, Davison TM, Chapman DJ, Eakins DE, Collins GSet al., 2018, Interrogating Heterogeneous Compaction of Analogue Materials at the Mesoscale Through Numerical Modeling and Experiments, 20th Biennial Conference of the Topical-Group of the American-Physical-Society (APS) on Shock Compression of Condensed Matter (SCCM), Publisher: AMER INST PHYSICS, ISSN: 0094-243X

CONFERENCE PAPER

Holm-Alwmark S, Rae ASP, Ferriere L, Alwmark C, Collins GSet al., 2017, Combining shock barometry with numerical modeling: Insights into complex crater formation-The example of the Siljan impact structure (Sweden), METEORITICS & PLANETARY SCIENCE, Vol: 52, Pages: 2521-2549, ISSN: 1086-9379

JOURNAL ARTICLE

Muxworthy AR, Bland PA, Davison TM, Moore J, Collins GS, Ciesla FJet al., 2017, Evidence for an impact-induced magnetic fabric in Allende, and exogenous alternatives to the core dynamo theory for Allende magnetization, METEORITICS & PLANETARY SCIENCE, Vol: 52, Pages: 2132-2146, ISSN: 1086-9379

JOURNAL ARTICLE

Kring DA, Claeys P, Gulick SPS, Morgan JV, Collins GSet al., 2017, Chicxulub and the Exploration of Large Peak-Ring Impact Craters through Scientific Drilling, GSA Today, Vol: 27, Pages: 4-8, ISSN: 1052-5173

The Chicxulub crater is the only well-preserved peak-ring crater on Earth and linked, famously, to the K-T or K-Pg mass extinction event. For the first time, geologists have drilled into the peak ring of that crater in the International Ocean Discovery Program and International Continental Scientific Drilling Program (IODP-ICDP) Expedition 364. The Chicxulub impact event, the environmental calamity it produced, and the paleobiological consequences are among the most captivating topics being discussed in the geologic community. Here we focus attention on the geological processes that shaped the ~200-km-wide impact crater responsible for that discussion and the expedition’s first year results.

JOURNAL ARTICLE

Jourdan F, Timms NE, Eroglu E, Mayers C, Frew A, Bland PA, Collins GS, Davison TM, Abe M, Yada Tet al., 2017, Collisional history of asteroid Itokawa, GEOLOGY, Vol: 45, Pages: 819-822, ISSN: 0091-7613

JOURNAL ARTICLE

Melosh HJ, Bland PA, Collins GS, Johnson BCet al., 2017, A SPECULATIVE "FIEFDOM" MODEL FOR CHONDRITE ORIGINS., 80th Annual Meeting of the Meteoritical-Society, Publisher: WILEY, Pages: A232-A232, ISSN: 1086-9379

CONFERENCE PAPER

Collins GS, Lynch E, McAdam R, Davison TMet al., 2017, A numerical assessment of simple airblast models of impact airbursts, METEORITICS & PLANETARY SCIENCE, Vol: 52, Pages: 1542-1560, ISSN: 1086-9379

JOURNAL ARTICLE

Watters WA, Hundal CB, Radford A, Collins GS, Tornabene LLet al., 2017, Dependence of secondary crater characteristics on downrange distance: High-resolution morphometry and simulations, JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS, Vol: 122, Pages: 1773-1800, ISSN: 2169-9097

JOURNAL ARTICLE

Rae ASP, Collins GS, Grieve RAF, Osinski GR, Morgan JVet al., 2017, Complex crater formation: Insights from combining observations of shock pressure distribution with numerical models at the West Clearwater Lake impact structure, METEORITICS & PLANETARY SCIENCE, Vol: 52, Pages: 1330-1350, ISSN: 1086-9379

JOURNAL ARTICLE

Forman LV, Bland PA, Timms NE, Daly L, Benedix GK, Trimby PW, Collins GS, Davison TMet al., 2017, Defining the mechanism for compaction of the CV chondrite parent body, GEOLOGY, Vol: 45, Pages: 559-562, ISSN: 0091-7613

JOURNAL ARTICLE

Rutherford ME, Chapman DJ, Derrick JG, Patten JRW, Bland PA, Rack A, Collins GS, Eakins DEet al., 2017, Probing the early stages of shock-induced chondritic meteorite formation at the mesoscale, SCIENTIFIC REPORTS, Vol: 7, ISSN: 2045-2322

JOURNAL ARTICLE

Collins GS, 2017, Moon formation: Punch combo or knock-out blow?, Nature Geoscience, Vol: 10, Pages: 72-73, ISSN: 1752-0894

JOURNAL ARTICLE

Smith R, 2017, Numerical modelling of tsunami generated by deformable submarine slides

Submarine slides can generate tsunami waves that cause significant damage and loss of life. Numerical modelling of submarine slide generated waves is complex and computationally challenging, but is useful to understand the nature of the waves that are generated, and identify the important factors in determining wave characteristics which in turn are used in risk assessments. In this work, the open-source, finite-element, unstructured mesh fluid dynamics framework Fluidity is used to simulate submarine slide tsunami using a number of different numerical approaches. First, three alternative approaches for simulating submarine slide acceleration, deformation and wave generation with full coupling between the slide and water in two dimensions are compared. Each approach is verified against benchmarks from experimental and other numerical studies, at different scales, for deformable submarine slides. There is good agreement to both laboratory results and other numerical models, both with a fixed mesh and a dynamically adaptive mesh, tracking important features of the slide geometry as the simulation progresses. Second, Fluidity is also used in a single-layer Bousinesq approximation in conjunction with a prescribed velocity boundary condition to model the propagation of slide tsunami in two and three dimensions. A new, efficient approach for submarine slide tsunami that accounts for slide dynamics and deformation is developed by imposing slide dynamics, derived from multi-material simulations. Two submarine slides are simulated in the Atlantic Ocean, and these generate waves up to 10 m high at the coast of the British Isles. Results indicate the largest waves are generated in the direction of slide motion. The lowest waves are generated perpendicular to the slide motion. The slide velocity and acceleration are the most important factors in determining wave height. Slides that deform generate higher waves than rigid slides, although this effect is of secondary importance f

THESIS DISSERTATION

Davison TM, Derrick JG, Collins GS, Bland PA, Rutherford ME, Chapman DJ, Eakins DEet al., 2017, Impact-induced compaction of primitive solar system solids: The need for mesoscale modelling and experiments, 14TH HYPERVELOCITY IMPACT SYMPOSIUM (HVIS 2017), Vol: 204, Pages: 405-412, ISSN: 1877-7058

JOURNAL ARTICLE

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