제주 날씨- Weather on Jeju Island

Jeju Island has the mildest weather in Korea, allowing tourists to visit all-year-long. Jeju Island resides 33.6’North and 126.5’ East on the Earth. By being near the equator, Jeju has a subtropical oceanic climate and temperate climate. According to Wladimir Koppen’s classification of climate, Jeju Island maintains a mild winter with consistent precipitation.

Ocean Currents

The climate is also due in part to the Kuroshio (north-flowing ocean current on the west side of the North Pacific Ocean) and Tshushima (warm branch of the Kuroshio current) current; they have a direct effect on the island. The translation of Kuroshio is The Black Current and is a reference to the deep blue of its water. 

The ocean currents surrounding Japan and Korea: 1. Kuroshio Current 2. Kuroshio extension 3. Kuroshio countercurrent 4. Tsushima Current 5. Tsugaru Current 6. Sōya Current 7. Oyashio 8. Liman Current

Both of these currents are a part of the North Pacific Ocean gyre (giant, circular ocean currents that are driven by subtropical high pressure). By being surrounded by the ocean, the temperature range is quite small, yet Jeju Island displays four distinct season.

The four distinct seasons displayed on Jeju Island. 

Jeju Island in April

Springtime occurs in mid-February to April leading into the summer typhoon season in late June to early July. The figure below is a graph illustrating annual climate in Jeju Island. The left y-axis represents temperature (in Celsius), the right y-axis shows precipitation (mm) and x-axis represents months of the year.

As you can see from the figure above, the warmest and rainiest months on Jeju Island are June-September. Throughout April, the most common forms of precipitation are moderate rain and light rain. In April, the average high is 17.5 degrees Celsius (63.4 degrees Fahrenheit), with the average low being 10.2 degrees Celsius (50.4 degrees Fahrenheit).

References

http://weatherspark.com/averages/33274/Jeju-Jeju-do-South-Korea 

http://weatherspark.com/averages/33274/4/Jeju-Jeju-do-South-Korea

http://english.jeju.go.kr/index.php/contents/AboutJeju/intro/weather 

http://travel.cnn.com/explorations/play/10-things-do-jeju-island-045157

http://www.asianinfo.org/asianinfo/korea/Jeju_Island

http://english.jeju.go.kr/index.php/contents/culture-nature/nature/geographical/climate

Hydrology on Jeju Island

“The Lung of Jeju”

Cheonjiyeon Waterfall on Jeju Island, South Korea, and one of the most popular tourist attractions on the island.

 

The Gotjawal Forest, located on the middle slopes of Mt. Hallasan is the main groundwater (water that moves in the pore spaces of rock beneath the surface) source for the entire island, a population of 565,000 people.

Covering an area of 86 square miles, the Gotjawal Forest has remained untouched until the mid 20th century. The base of the forest is a mixture of Pahoehoe (smooth, billowy, ropy surface) and ‘A’a (rough, jagged and clinkery surface) lava, both of which were created during the development of Mt. Hallasan

The lava mixture makes for a beautiful landscape. On the other hand, the Pahoehoe and ‘A’a lava have made it difficult to develop the land for agriculture. The rainwater on the island penetrates into their groundwater aquifer (an underground layer of water bearing rock where groundwater can be removed) through the cracks of the Pahoehoe and ‘A’a lava under the forest floor making it the most active aquifer in Korea.

 

(Side view of the aquifer cycle)
This is what happens in Gotjawal Forest when precipitation occurs.

Maintaining a balance of the water usage is essential to avoid drawdown, which is the process of depleting groundwater before it has time to recharge (the replenishing ground water as precipitation allows). This also creates a cone of depression (water levels around the well decrease).By successfully maintaining this balance achieves dynamic equilibrium (the balance between drawdown and recharge).

 

Example of a drawdown pump
and the development of a cone of depression.

The mixture of lava (Pahoehoe and ‘A’a) beneath the forest floor has created a layer of permeable (having pores or openings that permit liquids or gases to pass though) rock. 46 percent of the rainwater that falls over the Gotjawal Forest penetrates the aquifer, because of this there are no rivers on the east and west side of the island. The active aquifer has earned the Gotjawal Forest the nickname “The Lung of Jeju” and has made it unique throughout the region.







Saturated surface of the forest floor.

The Gotjawal Forest was named an Internationally Important Wetland in 2011 under the Ramsar Convention (intergovernmental treaty that works to maintain the ecological character of their Wetlands of International Importance and plan for the sustainable use of all the wetlands in their territories); because it is a habitat for unique plant species and a main source for groundwater.





Indian Pitta

Unfortunately, due to the development of the Gotjawal Forest in the 1980’s for golf courses and resorts researches say that development is the main cause for groundwater exhaustion and pollution. However, the only information shown to support this hypothesis is the decreasing habitats of birds and plant life. There are currently no efforts to protect the streams, plants, or the natural habitats of the birds; even some species like Indian Pittas who are classified as endangered by the Korean Government. 

References:

http://clasfaculty.ucdenver.edu/callen/1202/Battle/Destroy/Hydrology/HydrologyBasics.html

http://www.ramsar.org/cda/en/ramsar-about-about-ramsar/main/ramsar/1-36%5E7687_4000_0 

http://www.lovethesepics.com/2011/06/volcanic-jeju-island-of-the-gods-33-pics

http://www.jejuweekly.com/news/articleView.html?idxno=301

http://portals.iucn.org/2012forum/sites/2012forum/files/gotjawal.pdf

http://hvo.wr.usgs.gov/volcanowatch/archive/1999/99_05_27.html

 

Jeju: The Volcanic Island

 

“Jeju Island is Hallasan; and Hallasan is Jeju”

Mt. Hallasan

 

 

Mt. Hallasan, a shield volcano also adds to the landscape of Jeju Island including crater lakes and lava plains. It is the highest mountain in South Korea and the area around it has been labeled a national park. The lavas of this volcano cover the bulk of the island, so much to that it is taken to represent the whole island.  

The basalt volcanic form is the least dangerous of all the volcanoes. The low angle of the volcanic form and multiple lava flows lends to the lava plains.

Multiple Lava Flows

This volcano is still active but hasn’t erupted since 1570 A.D. Mt. Hallasan as well as the lava tubes have become major tourist attractions for the island. The summit has been free from any natural disasters like earthquakes. The peak of Mt. Hallasan a dome that was formed by intrusion and emplacement between 25,000-30,000 years ago.

 Lava Tubes

Lava Tubes

Jeju Island, already being a volcanic island is also comprised of lava tubes. Geomunoreum is looked upon as the finest lava tube system. It is regarded as a United Nations Educational, Scientific, and Cultural Organization (UNESCO) World Heritage Site.

Jeju and the lava tubes fall under two criteria for a World Heritage Site: exceptional natural beauty or natural phenomena and it reveals the Earth’s history through landforms, geology or record of life.

The lava tubes are some of the largest in the world. The island itself is important in biodiversity. Almost half of the plants that grow in the region of South Korea flourish the most on Jeju Island; another reason why it is registered as a World Natural Heritage Site.

There are more than 120 lava tubes throughout Jeju Island. They were formed with large amounts of basaltic lava that was given off by the Geomunoreum volcano. Some of the lava tubes contained artifacts from previous man, and have been used as a shelter or scared place.

References and Photos:

"Cultural Heritage, the Source for Koreans' Strength and Dream".Cultural Heritage, the Source for Koreans' Strength and Dream. Web. 14 Feb. 2013.

"Formation of Jeju Island - Jeju Special Self-Governing Province." Formation of Jeju Island - Jeju Special Self-Governing Province. N.p., n.d. Web. 12 Feb. 2013.

"Jeju Volcanic Island and Lava Tubes." - UNESCO World Heritage Centre. N.p., n.d. Web. 10 Feb. 2013.

"UNESCO Kids." The World Natural Heritage/UNESCO Kids. Web. 14 Feb. 2013.

http://www.vulcanospeleology.org/sym05gui/ISV5G07.pdf 

 

 

 

 

Jeju Island: Nature's Paradise in the North Pacific

This blog was created and will be maintained by Brittany Richardson.

My name is Brittany Richardson, I am a Senior undergraduate English/writing student at the University of Colorado Denver. The subject of this blog will be Jeju Island or Jeju Province, which is one of the nine provinces of South Korea. It is the nation's largest island and is a volcanic island that is dominated by Halla Mountain, a volcano, and the highest mountain in South Korea. I was supposed to visit this island during the summer on my study abroad trip, but it was too expensive for the amount of time that we had. So, the curiosity is still there, I guess. 

Mount Hallasan

After doing a bit of research before the trip began, I was fascinated by how an island that is only  45 miles long and 40 miles wide can sustain over half a million people!! Also, the forest is the main groundwater source and water source for the entire island. How has that sustained this population for so long? Will it cause problems in the near future? Hopefully, I can go back and visit this summer with some little known geographical facts! Looking forward to learning something new! 

Dol Hareubangs:
They are considered to be gods offering protection and fertility.