什么是“冰后地壳回弹”（isostatic rebound）？请举例。
What is post-glacial isostatic rebound, and can you give an example?
冰期时巨厚冰盖压沉了地壳（均衡沉降），冰盖消融后载荷减轻，地壳便缓慢回弹抬升，这一过程可持续数千年，称为冰后均衡回弹。现今斯堪的纳维亚和加拿大地盾仍在以每年数毫米到约1厘米的速度上升。
During ice ages, the enormous weight of ice sheets depressed the crust (isostatic subsidence); after the ice melts and the load is removed, the crust slowly rises again—a process lasting thousands of years called glacio-isostatic rebound. Today Scandinavia and the Canadian Shield are still rising by several millimeters to about a centimeter per year.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 已核验 · Verified 2026-08-23
来源 · Source
Tarbuck & Lutgens,《Earth Science》第14版,Pearson,2015
E. J. Tarbuck and F. K. Lutgens, Earth Science, 14th ed., Pearson, 2015
#地壳回弹 #均衡 #冰盖 #斯堪的纳维亚 #加拿大地盾
什么是峡湾？
What is a fjord?
峡湾是冰川侵蚀出的U形谷在冰川消退后被海水淹没形成的狭长海湾，两岸陡峭、水深很大。挪威和智利南部海岸以大量峡湾著称。
A fjord is a long, narrow inlet with steep sides and great depth, formed when a glacial U-shaped valley was flooded by the sea after the ice retreated. Coasts of Norway and southern Chile are famous for them.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 已核验 · Verified 2026-08-23
来源 · Source
Tarbuck & Lutgens,《Earth Science》第14版,Pearson,2015
E. J. Tarbuck and F. K. Lutgens, Earth Science, 14th ed., Pearson, 2015
#峡湾 #冰川谷 #海水淹没
冰是晶体固体，冰川为什么还能持续向下缓慢“流动”？其稳定应变速率与所受剪应力之间近似服从什么经验规律？
Ice is a crystalline solid, so why do glaciers still creep steadily downhill, and what empirical law links their steady-state strain rate to shear stress?
在长期剪应力作用下，冰晶内发生位错滑移并伴随动态重结晶与晶粒调整，产生持续累积的塑性应变，故冰川表现得像黏度极高的流体。实验与野外资料表明，其稳态应变速率大致与剪应力的三次方成正比，即格伦流动定律（n≈3）。因冰床附近剪应力最大，变形集中于底部；底面若有融水润滑，再叠加上滑动便形成快速冰流。
Under sustained shear stress, ice deforms by dislocation glide together with dynamic recrystallization, accumulating permanent plastic strain, so a glacier moves like an extremely viscous fluid. Experiments show the steady-state strain rate varies roughly as the third power of shear stress — Glen’s flow law (n ≈ 3). Shear stress peaks near the bed, concentrating deformation at the glacier base; where meltwater lubricates the bed, sliding is added on top, producing fast-flowing ice streams.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 已核验 · Verified 2026-11-03
来源 · Source
Glen, J.W.《多晶冰的蠕变》，《皇家学会会刊A辑》228卷1175期，1955年，DOI:10.1098/rspa.1955.0066
Glen, J.W., “The Creep of Polycrystalline Ice”, Proceedings of the Royal Society A, 228(1175), 1955, DOI:10.1098/rspa.1955.0066
独立核验依据 · Independent verification: 核验依据 1 CROSSREF 标识 10.1098/rspa.1955.0066：The creep of polycrys
#冰川学 #冰流 #蠕变 #格伦流动定律
冰川为什么会周期性地突然“跃动”？对瓦尔加特冰川的观测揭示了怎样的机制？
Why do certain glaciers suddenly surge in periodic episodes, and what did direct observations of Variegated Glacier reveal about the mechanism?
跃动冰川常年缓行，却会周期性暴发式加速数十倍。对阿拉斯加瓦尔加特冰川的观测显示：一旦冰下排水从高效的通道网络转为低效的分布式水系，融水积存、冰下水压骤升，底床有效正应力锐减，滑动与底床变形猛增，冰川整体前冲；其后隧道排水重建、水压回落，跃动随之终止。这种“水文开关”支配着跃动的开始与结束。
Surge-type glaciers creep along slowly yet periodically lurch forward at many times their normal speed. Observations of Variegated Glacier, Alaska, showed that when subglacial drainage switches from efficient conduit tunnels to an inefficient distributed cavity network, meltwater is stored and basal water pressure climbs; the effective normal stress on the bed collapses, letting sliding and bed deformation accelerate and propel the whole ice mass. Once tunnel drainage is rebuilt and pressure drops, the surge terminates—a hydrologic switch governing onset and end.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 已核验 · Verified 2026-11-02
来源 · Source
Kamb 等，“Glacier Surge Mechanism: 1982–1983 Surge of Variegated Glacier”，Science 227卷，1985，DOI: 10.1126/science.227.4686.469
Kamb et al., "Glacier Surge Mechanism: 1982-1983 Surge of Variegated Glacier, Alaska", Science 227, 1985, DOI: 10.1126/science.227.4686.469
独立核验依据 · Independent verification: 核验依据 1 CROSSREF 标识 10.1126/science.227.4686.469：Glacier Surge M
#冰川跃动 #底部滑动 #冰下水文
海冰、冰架和冰盖有什么区别？
How do sea ice, ice shelves, and ice sheets differ?
海冰是海面直接冻结的浮冰，冰架是连在陆地冰盖、伸入海中的浮冰平台，冰盖则是覆盖大陆的巨厚冰体。前两者漂浮不直接影响海平面，冰盖融化则会抬升海平面。
Sea ice is frozen ocean surface that floats, an ice shelf is a floating platform of ice attached to and fed by a land ice sheet, and an ice sheet is a vast thick ice mass over a continent. The first two float and don't directly raise sea level; melting ice sheets does.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 已核验 · Verified 2026-08-23
来源 · Source
Tarbuck & Lutgens,《Earth Science》第14版,Pearson,2015
E. J. Tarbuck and F. K. Lutgens, Earth Science, 14th ed., Pearson, 2015
#海冰 #冰架 #冰盖
什么是冰冻圈？
What is the cryosphere?
冰冻圈是地球表层所有以固态水存在的部分，包括冰川、冰盖、海冰、积雪和永冻层。它对全球能量平衡和海平面变化起着关键作用。
The cryosphere is all the frozen water at Earth's surface—glaciers, ice sheets, sea ice, snow, and permafrost. It plays a central role in the global energy balance and sea-level change.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 已核验 · Verified 2026-08-23
来源 · Source
Tarbuck & Lutgens,《Earth Science》第14版,Pearson,2015
E. J. Tarbuck and F. K. Lutgens, Earth Science, 14th ed., Pearson, 2015
#冰冻圈 #冰雪 #能量平衡
格陵兰和南极冰盖有多重要？
Why are the Greenland and Antarctic ice sheets important?
这两大冰盖储存了地球上绝大部分的陆地冰，若全部融化可使全球海平面上升数十米。它们的质量变化也通过融水影响大洋环流与气候。
These two ice sheets hold most of Earth's land ice, and if fully melted could raise global sea level by many tens of meters. Their changing mass also affects ocean circulation and climate through meltwater input.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 已核验 · Verified 2026-08-23
来源 · Source
Tarbuck & Lutgens,《Earth Science》第14版,Pearson,2015
E. J. Tarbuck and F. K. Lutgens, Earth Science, 14th ed., Pearson, 2015
#冰盖 #海平面 #融水
冰川如何侵蚀地表？
How do glaciers erode the land?
冰川移动时像砂纸一样磨蚀和拔蚀基岩，把碎屑裹入冰中带走。它常雕出U形谷、冰斗和由堆积物构成的终碛堤（冰碛）。
As glaciers move they scrape and pluck at bedrock like sandpaper, carrying debris within the ice. They carve U-shaped valleys and cirques and leave ridges of deposited debris called moraines.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 已核验 · Verified 2026-08-23
来源 · Source
Tarbuck & Lutgens,《Earth Science》第14版,Pearson,2015
E. J. Tarbuck and F. K. Lutgens, Earth Science, 14th ed., Pearson, 2015
#冰川侵蚀 #U形谷 #冰碛
海平面上升的主要原因是什么？
What mainly causes sea-level rise?
海平面上升主要来自两方面：海水受热膨胀（热膨胀）和陆地冰川、冰盖融化注入海洋。两者都随全球变暖而加剧，威胁沿海城市与岛屿。
Sea level rises mainly for two reasons: ocean water expands as it warms (thermal expansion) and land ice melts into the sea. Both are amplified by global warming, threatening coasts and islands.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 已核验 · Verified 2026-08-23
来源 · Source
Tarbuck & Lutgens,《Earth Science》第14版,Pearson,2015
E. J. Tarbuck and F. K. Lutgens, Earth Science, 14th ed., Pearson, 2015
#海平面上升 #热膨胀 #融冰
山地冰川和大陆冰川有何不同？
How do alpine and continental glaciers differ?
山地冰川（谷冰川）限于山谷中，受地形约束流动；大陆冰川则覆盖广阔大陆，如南极和格陵兰冰盖，厚度可达数千米。前者塑造峡谷，后者影响全球海平面。
Alpine (valley) glaciers are confined to mountain valleys and flow with the terrain, while continental glaciers blanket huge land areas like the Antarctic and Greenland ice sheets, kilometers thick. The former carve canyons; the latter affect global sea level.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 已核验 · Verified 2026-08-23
来源 · Source
Tarbuck & Lutgens,《Earth Science》第14版,Pearson,2015
E. J. Tarbuck and F. K. Lutgens, Earth Science, 14th ed., Pearson, 2015
#山地冰川 #大陆冰川 #冰盖
冰川是如何形成并移动的？
How do glaciers form and move?
当高纬或高山的降雪在年内积累量超过消融量，雪被压实成粒雪（firn）并最终重结晶为冰川冰。冰川通过两种主要方式移动：底部滑动（冰与基岩界面融水润滑）和内部塑性变形（冰在自身重力下缓慢流动）。
Where snowfall accumulates faster than it melts in cold high latitudes or mountains, snow compacts into firn and eventually recrystallizes into glacial ice. Glaciers move mainly by basal sliding (lubricated by meltwater at the bed) and internal plastic deformation (ice flowing slowly under its own weight).
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 已核验 · Verified 2026-08-23
来源 · Source
Tarbuck & Lutgens,《Earth Science》第14版,Pearson,2015
E. J. Tarbuck and F. K. Lutgens, Earth Science, 14th ed., Pearson, 2015
#冰川 #粒雪 #冰川冰 #底部滑动 #塑性变形
什么是冰川？
What is a glacier?
冰川是陆地上多年积累、在自身重力作用下缓慢流动的大体量冰体。它既塑造山谷与海岸，也是全球淡水的重要储存库。
A glacier is a large body of ice on land that has built up over years and moves slowly under its own weight. It both sculpts valleys and coasts and stores a large share of the world's freshwater.
难度 入门 · 适合 小学高段(9-12)
CC BY 4.0 · 已核验 · Verified 2026-08-23
来源 · Source
Tarbuck & Lutgens,《Earth Science》第14版,Pearson,2015
E. J. Tarbuck and F. K. Lutgens, Earth Science, 14th ed., Pearson, 2015
#冰川 #冰体 #流动