#mt. halla

Jeju Island, South Korea

Jeju (sometimes known as Samdado) is a small volcanic island off the southwest coast of South Korea. In 2007 it was recognised as a UNESCO World Heritage site because of it's geology. The island was formed 2 million years ago and is still considered active.

Mt. Halla (Hallasan) is one of the only large shield volcanoes to form over a stationary continental plate hot spot. While the mountain has the typical shield volcano morphology, is actually a shelfal shield volcano that initially formed from shallow water, phreatomagmatic eruptions. These are explosive due to the direct mixing of lava with water. As the volcano built up above sea level, the eruptions became effusive and formed the shield volcano we know today. The first image shows the sun setting over Mt. Halla.

The Geomunoreum Lava Tubes are considered to be some of the most spectacular anywhere and is home to the world's longest lava tube. The tubes feature a diverse and abundant collection of secondary carbonate speleothems, the likes of which are not found anywhere else. The second image shows some of these carbonate formations.

Seongsang Ulchulbong (sometimes called Ilchulbong) peak is considered to be an important site as it showcases the stratigraphy of Surtseyan-type volcanoes which form during phreatomagmatic eruptions in shallow waters (including interaction with continental aquifers). They are essentially the marine (generally speaking) counterpart to Strombolian-type volcanoes and are characterised by layers of very fine-grained ash, lapilli and bombs. The third image shows a profile view of Seongsan Ulchulbong, while the fourth is a closer view of the fine ash layers as seen elsewhere on the island.

YK

Image credits: Sun setting over Mt. Halla - By Justin De La Ornellas (https://flic.kr/p/7Tyq5x). Used under CC licensing. Speleothems in lava tubes - By Republic of Korea (https://flic.kr/p/a7EZSr). Used under CC licensing. Seongsan Ilchubong - by Austronesian Expeditions (https://flic.kr/p/asQBW3). Used under CC licensing. Layers of ash at the Gosan-ri Geological Park - By Jeon Han (https://flic.kr/p/pWh7Jb). Used under CC licensing.

JEJU 16 — Volcanic Bedrock Water Review

Who knew that water wasn’t just… well, water. What seems a fairly simple product now has me thinking more about this basic staple item. Before receiving the opportunity to review Jeju 16 water, basically all I knew about water was that filtered is generally considered to be better for you than tap, with a side controversy indicating that some bottled waters are better than others depending on…