Karst Topography In South Thailand

We came across Karst Caves on our 14-day Thailand and Cambodia trip itinerary to Thailand. We flew from Delhi to Bangkok. After a short trip to Cambodia, we headed to south Thailand. We stayed in Koh Tao for 5 days and then traveled to Phuket. While in Phuket we took a day tour of Phang Nga Bay. Here we came across some amazing Karst landscapes and caves. Ice Cream Cave particularly was spectacular.

Koh Tao to Phuket was almost a day journey. We took a sleeper boat from Koh Tao to Surat Thani - Our memorable sleeper boat ride from Koh Tao to Surat Thani. At Surat Thani Pier, we got a bus to Phuket. 

Phang Nga Bay tour was a day tour. We started early around 7:30 a.m. and came back around 5:00 p.m. We hopped a few islands in the bay and took a canoe ride to the Ice cream caves on Koh Panak Island

Phang Nga Bay has around 42 islands. The tour took us to Panak, Hong, and James Bond Island. The rest of the islands were cruised around

Phang Nga Bay Ice Cream Cave is a Karst formation. This Cave is one of the most breathtaking natural wonders of the world. When the Canoe entered the tiny cave, I did not for once imagine, it would eventually lead to an area open to the sky and surrounded by karst mountains covered in green foliage. It was a surreal experience 

Cave entrance in front. It looked so tiny from the outside but the surprise inside was overwhelming.

The Sinkhole formation: Open to sky enclosed within tall karst mountains. My photos do not do justice but the experience is uncapturable

Phang Nga Bay islands: Of the 42+ islands in the bay, 14 are the most visited which include Khao Phing Kan (James Bond Island), Koh Panak, Koh Hong, Koh Yao Yai, Koh Kudu Yai, Koh Panyee, Koh Nom Sao, Koh Raya ring to name a few. 'Khao' in Thai means 'hill' and 'Koh' means 'Island'.

What is Karst Topography

A Karst landscape is a formation in regions that have large deposits of limestone / or any calcium-rich stone, abundant water, and rich vegetation. Calcium-rich stone reacts with atmospheric CO2 and carbon dioxide released by plants and aquatic organisms to form porous layers through which water seeps into the ground creating underground subterranean rivers, lakes, and caves with stalactite and stalagmites. These natural wonders are like sculptures designed by nature.

Stalactite in Phang Nga Bay Cave: Water-dripped mineral deposits that form icicle-like formations hanging down the cave roofs are called stalactite

Stalagmite and karst columns at Panak Islands: Stalagmites are icicle-type water-dripped mineral deposits formed on floors of caves. These grow upward and form columns when joined with stalactites growing downwards.

Stalactites- A closer look - water droplets can be seen on the tips

Karst columns - a closer look

Green fluorescent light in the ice cream caves due to the reflection of light through green algae water 

Khao Phing Kan, popularly known as James Bond Island after the shooting of the 007 Movie, The Man with the Golden Gun

Ko Hong Islands

Prominent Karst Regions in Thailnd. Doi Nang Non is the karst region in the north. It became famous when 12 junior football team members and their coach got trapped inside one of the caves and were rescued over a 12-day period.

Karst landscape in Croatia

Karst Topography in Croatia: Plitvice Lakes

How were the Plitvice lakes formed?

How Were The Plitvice Lakes And Waterfalls Formed?

Plitvice Lakes: Tufa or Meteogene Travertine or Sedra (Croatian term): It is a porous variety of limestone deposits formed on waterbeds when calcium-rich water bodies create carbonates which form sticky layers on moss and algae present in the water. Over the years, these deposits form tower-like formations

Thermogene Travertine in Yellow Stone National Park

 Meteogene travertine (Tufa) vs Thermogene travertine

The main difference between meteogene travertine and thermogene travertine is that one is formed in unheated conditions and one is formed in a heated condition. Meteogene travertine is highly porous and spongy and is formed in cooler temperatures while thermogene travertine is less in porosity and needs very high temperatures for its formation. Meteogene travertine is a result of atmospheric and epigeal activities while thermogene travertine is a result of volcanic activities.

Source of image: Link The Plitvice region receives abundant rain feeding a continuous supply of water to the lakes and rivers which are rich in moss and algae which in turn supply carbon dioxide. The rich forest cover provides an abundance of oxygen which helps sustain life forms in the region. The Dolomite and Limestone rich soil supplies a high volume of calcium-rich ions. 

Process of Tufa creation

Ca++ (calcium ions in calcium rich water and soil) + H2O (water) = Ca(OH)2  (Calcium hydroxide)

Ca(OH)2 +CO2 (carbon dioxide from atmosphere and the aquatic life) = CaCO3 (calcium carbonate limestone / tufa) +H2O

In simple words, quicklime when mixed with water forms calcium hydroxide. This in turn converts to calcium carbonate when Carbon dioxide released by the aquatic organisms reacts with calcium hydroxide. The carbon dioxide released by the underwater organisms gets released to the surface in the colder seasons. The calcium carbonate deposits which are insoluble in water then start depositing on the moss and algae on the water surface eventually forming porous, spongy tufa. 

Tufa towers eventually form small tower-like structures creating barriers in the flowing water thus forming a series of lakes and waterfalls.

Karst in South Thailand

A landscape rich in tufa is called Karst. The main features of Karst topography are the abundance of soluble calcium in the form of limestone, dolomites, gypsum, etc,  clean water full of aquatic organisms and lifeforms, and a landscape with sink holes, fissures, underground streams, and caves.

Picture source: Link

More about Plitvice Lakes and Waterfalls