ヒマラヤの巨大な山頂が,大地滑りで崩壊した中世
Jérôme Lavé1, Cyrielle Guérin2, Pierre G Valla3
1CRPG, CNRS, Université de Lorraine, Vandœuvre-lès-Nancy, France. jlave@crpg.cnrs-nancy.fr.
Nature
|July 5, 2023
まとめ
ヒマラヤの高い山頂が 高さを失っているのは 典型的な侵食ではなく 巨大な岩崩れによるものです このプロセスはおそらく永久凍土によって引き起こされ 景観を劇的に変えて 川の堆積物量に影響します
科学分野:
- 地形学
- 氷河学
- 構造学
背景:
- ヒマラヤの侵食メカニズムは 極端な高さでは 十分に理解されていません
- 氷河侵食は渓谷の床を支配していますが,高地での氷河侵食はあまり激しくありません.
- これは,最も高い峰の侵食率の低下を示唆し,長期の地質学的安定性を疑問視しています.
研究 の 目的:
- ヒマラヤの非常に高い山頂に影響を与える侵食過程を調査する.
- ピーク高さの増加を制限する潜在的メカニズムを特定する.
- 高地での大量流出による地形と堆積物の影響を理解する.
主な方法:
- アナプルナ山脈の大規模な岩崩れ事故の地質調査
- 岩崩れ事件の放射線年代測定
- 岩石の滑落の量と山頂の高さへの影響の分析
主要な成果:
- 西暦1190年頃の大規模な岩石流落の証拠で,約23立方キロメートルの岩石が含まれています.
- 岩石の滑落により 8000mを超える高さの古山が崩壊しました
- この現象は メガ・ロックスライドが 重要な高地浸食過程であることを示唆しています
結論:
- ヒマラヤの高い山頂を侵食し 過剰な成長を防ぐ主なメカニズムです
- 高地での永久凍土は,ピーク基板の機械的な強さに寄与し,大きな岩崩れを容易にします.
- これらの現象は,かなりの堆積物を生成し,下流の渓谷と川系に長期間影響を与える.
関連する概念動画
Threats to Biodiversity
22.4K
There have been five major extinction events throughout geological history, resulting in the elimination of biodiversity, followed by a rebound of species that adapted to the new conditions. In the current geological epoch, the Holocene, there is a sixth extinction event in progress. This mass extinction has been attributed to human activities and is thus provisionally called the Anthropocene. In 2019 the human population reached 7.7 billion people and is projected to comprise 10 billion by...
22.4K
Ecological Succession
17.3K
Ecological succession is influenced by the processes of facilitation, inhibition, and toleration. Facilitation occurs when early successional species create more favorable ecological conditions for subsequent species, such as enhanced nutrient, water, or light availability. In contrast, inhibition happens when early successional species create unfavorable ecological conditions for potential successive species, such as limiting resource availability. In some cases, later successional species...
17.3K
Global Climate Change
24.5K
Throughout its ~4.5 billion year history, the Earth has experienced periods of warming and cooling. However, the current drastic increase in global temperatures is well outside of the Earth’s cyclic norms, and evidence for human-caused global climate change is compelling. Paleoclimatology, the study of ancient climate conditions, provides ample evidence for human-caused global climate change by comparing recent conditions with those in the past.
24.5K
Conservation of Energy: Application
7.0K
When solving problems using the energy conservation law, the object (system) to be studied should first be identified. Often, in applications of energy conservation, we study more than one body at the same time. Second, identify all forces acting on the object and determine whether each force doing work is conservative. If a non-conservative force (e.g., friction) is doing work, then mechanical energy is not conserved. The system must then be analyzed with non-conservative work. Third, for...
7.0K
Impact: Problem Solving
247
In an experiment conducted during a Mars mission, a rover propels a projectile with an initial velocity, and the projectile rebounds after colliding with the Martian surface. To ascertain the maximum height attained by the projectile after this collision, the known restitution coefficient and acceleration due to gravity are employed.
By designating the launch point as the origin and utilizing kinematic equations, the vertical component of the projectile's velocity at the point of impact is...
By designating the launch point as the origin and utilizing kinematic equations, the vertical component of the projectile's velocity at the point of impact is...
247
Survival Tree
117
Survival trees are a non-parametric method used in survival analysis to model the relationship between a set of covariates and the time until an event of interest occurs, often referred to as the "time-to-event" or "survival time." This method is particularly useful when dealing with censored data, where the event has not occurred for some individuals by the end of the study period, or when the exact time of the event is unknown.
Building a Survival Tree
Constructing a...
Building a Survival Tree
Constructing a...
117


