An Experimental Investigation of the Effect of Grain Size on "Dislocation Creep" of Ice
文献类型：期刊论文
| 作者 | Qi, Chao1,2; Goldsby, David L.1 |
| 刊名 | JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
 |
| 出版日期 | 2021-09-01 |
| 卷号 | 126期号:9页码:15 |
| 关键词 | ice rheology dislocation creep grain boundary sliding creep |
| ISSN号 | 2169-9313 |
| DOI | 10.1029/2021JB021824 |
| 英文摘要 | The creep behavior of ice is believed to be dominated by dislocation creep at high stresses (>1 MPa) and high homologous temperatures (>0.9). Dislocation creep of ice is often described by the Glen law, epsilon?=B sigma n, with a canonical value of n= 3, and is independent of grain size. Laboratory studies of ice deformation at elevated pressures, however, suggest that dislocation creep of ice is characterized by a value of n approximate to 4. Here, we deformed ice samples with initial grain sizes of 0.23 and 0.63 mm, at 263 K and confining pressures of 10 or 20 MPa. The experiments yield a value of n= 3.6 using the peak stresses obtained at a strain epsilon approximate to 0.02, and reveal a marked dependence of the stress on initial grain size. The nominally constant flow stresses at larger strains, up to 0.2, yield a value of n= 3.9, and no influence of the initial grain size on the stress is observed. The lower value of n at peak stresses and the decrease in peak stress with decreasing initial grain size suggest a contribution to the strain rate from a grain-size-sensitive process, such as grain boundary sliding. Our data yield two flow laws, one for isotropic ice and one for highly anisotropic ice deformed to large strains, the latter of which may be used to model flow in high-strain natural environments. |
| WOS关键词 | MECHANICAL-PROPERTIES ; DEFORMATION ; TEMPERATURE ; STRESS ; RHEOLOGY ; ROCK ; FLOW |
| 资助项目 | NASA[NNX15AM69G] ; NSFC[41972232] |
| WOS研究方向 | Geochemistry & Geophysics |
| 语种 | 英语 |
| WOS记录号 | WOS:000703087900043 |
| 出版者 | AMER GEOPHYSICAL UNION |
| 资助机构 | NASA ; NASA ; NASA ; NASA ; NSFC ; NSFC ; NSFC ; NSFC ; NASA ; NASA ; NASA ; NASA ; NSFC ; NSFC ; NSFC ; NSFC ; NASA ; NASA ; NASA ; NASA ; NSFC ; NSFC ; NSFC ; NSFC ; NASA ; NASA ; NASA ; NASA ; NSFC ; NSFC ; NSFC ; NSFC |
| 源URL | [http://ir.iggcas.ac.cn/handle/132A11/102712]  |
| 专题 | 地质与地球物理研究所_中国科学院地球与行星物理重点实验室 |
| 通讯作者 | Qi, Chao |
| 作者单位 | 1.Univ Penn, Dept Earth & Environm Sci, Philadelphia, PA 19104 USA 2.Chinese Acad Sci, Inst Geol & Geophys, Key Lab Earth & Planetary Phys, Beijing, Peoples R China |
| 推荐引用方式 GB/T 7714 | Qi, Chao,Goldsby, David L.. An Experimental Investigation of the Effect of Grain Size on "Dislocation Creep" of Ice[J]. JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH,2021,126(9):15. |
| APA | Qi, Chao,&Goldsby, David L..(2021).An Experimental Investigation of the Effect of Grain Size on "Dislocation Creep" of Ice.JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH,126(9),15. |
| MLA | Qi, Chao,et al."An Experimental Investigation of the Effect of Grain Size on "Dislocation Creep" of Ice".JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH 126.9(2021):15. |
入库方式： OAI收割
来源：地质与地球物理研究所
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