5. The Formation of Mountains: Geological Forces at Work
Mountains are among the most awe-inspiring natural features on Earth, formed through a combination of geological processes that shape the planet’s surface over millions of years. These towering landforms are primarily created by tectonic forces, volcanic activity, and erosion, each contributing to the diverse range of mountain types found across the globe.
The most common mechanism behind mountain formation is tectonic activity, which occurs when massive sections of the Earth’s lithosphere, known as tectonic plates, move and interact. When two plates collide, they generate immense pressure that forces the crust upward, forming fold mountains such as the Himalayas. These mountains, some of the tallest in the world, continue to rise as the plates press against each other. Conversely, when plates pull apart, block mountains can form as large sections of the crust break and shift vertically along faults. Examples of such formations include the Sierra Nevada range in North America.
Tectonic activity not only creates mountains but also influences seismic activity, with earthquakes frequently occurring in tectonically active regions. Scientists use seismic data and GPS mapping to monitor these movements and predict potential geological hazards.
Another significant contributor to mountain formation is volcanic activity. Volcanic mountains are formed when molten rock, or magma, rises to the Earth’s surface through fractures in the crust. Upon cooling, the magma solidifies, creating mountains such as Mount Fuji in Japan and Mount St. Helens in the United States. Unlike fold mountains, volcanic mountains can develop relatively quickly, often growing with each successive eruption.
Volcanic activity is not only responsible for mountain formation but also plays a critical role in shaping landscapes through lava flows and ash deposits. These materials can enrich the soil, making volcanic regions highly fertile for agriculture. However, eruptions can also pose significant risks to nearby populations, requiring constant monitoring and early warning systems.
Once mountains are formed, they are continuously shaped and reshaped by erosion and weathering. Wind, water, and ice gradually wear down mountain surfaces, transporting sediment and altering their appearance over time. Glacial erosion, in particular, is a powerful force that carves deep valleys and sharp ridges in mountain landscapes, such as those seen in the European Alps.
Weathering processes further contribute to the breakdown of rock materials, preparing them for transport by agents of erosion. Chemical weathering, driven by interactions with water and atmospheric gases, gradually weakens rock formations, while physical weathering processes, such as freeze-thaw cycles, cause mechanical breakdown of rock surfaces.
Mountains exert significant influence on regional climate patterns by acting as barriers to atmospheric circulation. When moist air masses encounter a mountain range, they are forced to rise, cooling and condensing to produce precipitation on the windward side. This phenomenon, known as orographic rainfall, creates lush vegetation and water resources. In contrast, the leeward side of the range often experiences dry conditions, leading to the formation of rain shadows.
Additionally, mountains provide unique habitats for diverse plant and animal species adapted to extreme conditions. These ecosystems, often referred to as alpine environments, host a variety of flora and fauna that have evolved to withstand low temperatures, high altitudes, and limited oxygen availability.
Advancements in technology have greatly enhanced our ability to study and monitor mountain formation processes. Scientists utilize satellite imagery, GPS mapping, and remote sensing techniques to track tectonic movements and volcanic activity. Such research is crucial for understanding Earth’s geological history and preparing for potential natural disasters associated with mountain formation processes.
Future research in the field aims to develop improved predictive models for earthquakes and volcanic eruptions, ensuring better preparedness and resilience for communities living in mountainous regions. (597 Words)
Table Completion Questions
Complete the table below. Choose NO MORE THAN THREE WORDS AND/OR A NUMBER from the passage for each answer.
Aspect
Process
Example
Tectonic Activity
Caused by plate (1) _____
Formation of the (2) __________
Volcanic Activity
Magma reaches (3) ______
Creates peaks like (4) __________
Erosion
Due to water, wind, and (5) ______
Carves valleys and shapes mountains
Monitoring
Utilizes GPS and (6) ______
Tracks tectonic changes
Answer Key and Explanation
collision Hint: The passage states, “When tectonic plates collide, they force the Earth’s crust upward.”
Himalayas Hint: It mentions that the Himalayas were formed due to tectonic activity.
surface Hint: The passage describes how magma rises to the surface and solidifies to form mountains.
Mount Fuji Hint: Examples of volcanic mountains mentioned include Mount Fuji.
ice Hint: The passage mentions wind, water, and ice as factors causing erosion.
satellite imagery Hint: The passage states that advanced technologies such as satellite imagery and GPS help monitor tectonic activity.
パッセージ（抜粋）： “The recent study conducted by Dr. Smith revealed that a balanced diet can significantly improve cognitive functions in children under the age of 12. The research emphasizes the importance of including omega-3 fatty acids found in fish for brain development.”
問題文： 1. Dr. Smith’s study highlights the role of a __________ diet in enhancing children’s brain functions. 2. The research stresses the necessity of __________ for brain growth, which can be sourced from fish.
解答ヒント：
問題文1のヒント：
「diet」がキーワード。
「a __________ diet」の空所には形容詞が入る。
パッセージには「a balanced diet」とあるため答えはbalanced。
問題文2のヒント：
「brain growth」と「fish」に関連する語を探す。
パッセージに「omega-3 fatty acids found in fish」とあるため答えはomega-3 fatty acids。
解答：
balanced
omega-3 fatty acids
TIPS:
制限語数を守る 「NO MORE THAN TWO WORDS」と指定されていれば、解答は1～2語に限定します。
パッセージ（抜粋）： “The study of urban ecosystems has revealed significant effects of human activity on biodiversity. Cities often cause habitat loss, but they also create opportunities for certain species to thrive. Green roofs and urban gardens, for example, provide essential habitats for pollinators such as bees and butterflies.”
問題文： Summary: Human activities significantly impact biodiversity in cities. While urbanization can result in __________ (1), it can also offer benefits for some species. For instance, green roofs and urban gardens support __________ (2) like bees and butterflies.
解答ヒント：
1. 空所(1)のヒント：
空所の直前に「urbanization can result in」とあるため、「都市化がもたらす結果」を探す。
パッセージには「Cities often cause habitat loss」と記載されているため、答えはhabitat loss。
2. 空所(2)のヒント：
「support」の対象となる語句を探す。
パッセージには「pollinators such as bees and butterflies」とあるため、答えはpollinators。
