Geomorfologi Bentuklahan Karst

Summary

This educational video from the Geography Education Program at Universitas Negeri Yogyakarta explores geomorphology, focusing on karst landscapes. The video introduces the concept of karst, derived from German and Slovenian terms, and discusses the process of karstification, highlighting the importance of soluble rock types like limestone. It covers the distinctive features of karst terrain, such as closed depressions (dolina), karst hills, and caves, with real-life examples from the Gunung Sewu karst area. The video also delves into factors influencing karst formation, including rainfall, rock composition, and vegetation. Additionally, it emphasizes the high potential for groundwater in karst regions, despite their arid appearance.

Takeaways

• 😀 Karst refers to landforms created by the dissolution process, commonly involving limestone, gypsum, and salt rock.
• 😀 The term 'karst' comes from the Slovenian word for barren, rocky land and is used internationally to describe these landscapes.
• 😀 Karst landscapes are often associated with dry, rocky terrain but also contain significant water resources.
• 😀 Karst formation, known as 'karstification,' involves various factors, including the type of rock and environmental conditions.
• 😀 Key factors for karst formation include the presence of soluble rocks, sufficient rainfall (over 250 mm annually), and the exposure of rocks at higher elevations.
• 😀 Karstification is influenced by temperature and forest cover, with dense forests increasing CO2 in water, accelerating the process.
• 😀 In tropical regions, karst landscapes evolve quickly, leading to irregular depressions known as 'dolina' or 'sinkholes.'
• 😀 Karst morphology includes both exokarst (surface features like sinkholes and hills) and endokarst (underground features like caves and stalactites).
• 😀 Karst hills, or 'keke,' are characterized by low height and gentle slopes, often isolated in valleys.
• 😀 Differences in karst morphology, such as isolated hills or linked hills, are due to variations in the type of limestone and its rate of dissolution.
• 😀 Underground rivers play a vital role in draining water through karst landscapes, making the region's groundwater resources highly significant but difficult to access.

Q & A

What is the definition of 'kars' in geomorphology?

Kars is a term from German, used internationally to describe landforms formed by dissolution or solubility processes, typically characterized by barren, rocky terrains.

What is the origin of the word 'kars'?

The term 'kars' comes from the Slovenian word 'kraš', meaning a barren, rocky land. It is derived from the pre-Indo-European root 'kar' or 'gaara', meaning rock.

Why is 'kars' often associated with limestone?

Kars is most commonly found in limestone areas because limestone is highly soluble and prone to the dissolution processes that create typical karst landscapes. However, kars can also form in other soluble rocks such as gypsum and salt.

What are the key features of a karst landscape?

Key features of a karst landscape include closed depressions, rare or no surface rivers, and subterranean rivers. The terrain often includes dolines, hills, and underground caves.

What are the controlling factors in karst formation?

The controlling factors for karst formation include the type of soluble rock (such as limestone), the presence of fractures or cracks in the rock, rainfall (above 250 mm/year), and elevation, which influences vertical drainage.

How does vegetation affect karstification?

Vegetation plays a crucial role in karstification by producing CO2, which, when combined with rainwater, forms acidic water that accelerates the dissolution of soluble rocks, speeding up the karstification process.

What is karstification?

Karstification is the process of landscape formation through the dissolution of soluble rocks such as limestone, leading to features like caves, sinkholes, and underground rivers.

What are the differences between Exo-Kars and Indo-Kars morphologies?

Exo-Kars morphologies include external features like dolines, hills, and karst ridges, while Indo-Kars refers to internal karst features such as caves and speleothems (cave formations like stalactites and stalagmites).

What are the key characteristics of the Gunung Sewu karst area?

Gunung Sewu karst is characterized by bumpy, irregular landforms, including dolines with star-like shapes and karst hills surrounded by wide valleys. It is an example of tropical karst with rapid landscape development.

How do the types of limestone affect the karstification process?

The type of limestone influences the rate of karstification. Softer limestone leads to faster dissolution and more rapid formation of karst features, while harder limestone results in slower karstification and more resilient formations.