史费拉裂缝浮潜旅行团｜冰岛特色体验：左手欧洲，右手美洲（干潜水衣 ）

辛格维利尔国家公园，又译辛格韦德利国家公园，是冰岛大陆上唯一被联合国教科文组织认证为世界文化遗产的地点。它和盖歇尔间歇泉、黄金瀑布，组成了著名的黄金圈旅游线路。公园南侧是冰岛最大的湖泊－辛格瓦德拉湖（Þingvallavatn）。

地理

辛格维利尔的地理地质特性在世界上独一无二。欧亚大陆板块与美洲大陆板块在此相会，且暴露在海平面之上。全世界只能在冰岛看到两大地质板块在海平面之上相会的地质奇观。

游览时，建议从美洲大陆板块一侧开始观光，在这里的信息牌上可以阅读到这个地区的更多有趣信息和历史，之后可以再走入其下的山谷。

历史

辛格维利尔在冰岛语中的意思为“议会土地”，从它的名字就不难猜出它的历史。在这里，世界上的第一个民主议会诞生－公园930年，维京人选址在此，创立了冰岛的议会。

民主议会也许和维京人喜欢战争掠杀的名声背道而驰，但当时的30多个氏族急需在恶劣的新环境中求得生存与繁荣。第一次集会的空前成功，让议会得以保留。每年，人们聚集在此，解决争端、审判罪犯、制定让所有人都能受益的法律。

冰岛联邦就此诞生，让冰岛人在成为挪威王国的选民前就获得了独立与自由。冰岛在辛格维利尔的年度议会一直延续到了1798年。

丹麦王国取消了冰岛的议会，直至1845年，冰岛的议会在雷克雅未克重生。

辛格维利尔在冰岛历史上的另一个重要角色与信仰有关，公园1000年，挪威入侵冰岛，冰岛人在辛格维利尔舍弃异教信仰、北欧众神，转而投信基督教。

冰岛的法律演讲人、议长Þorgeir Ljósvetningagoði是冰岛的这场信仰危机中起到了决定性的作用，他考虑了一天一夜，才回到这里宣布了他的决定。

为了见证冰岛信仰的转变，Þorgeir将北欧众神的神像抛入北部的众神瀑布－Goðafoss，瀑布正得名于此。

丝浮拉裂缝

辛格维利尔是冰岛最受欢迎的自然景点之一，而除了上述的自然、历史原因，它还有另一大独特的景观－丝浮拉裂缝（Silfra，又译史费拉裂缝）。丝浮拉裂缝流淌着冰川水，是世界上排名前十的浮潜、潜水地。

丝浮拉在冰岛语中意为“银”，是公园内的一个水下峡谷，能见度高达100余米，温度常年保持在零上。世界各地的人们在这里穿上潜水衣，去水下享受完美的失重感，以及遨游在两大地质板块间的难得体验。

Silfra is a fissure filled with fresh spring water within Þingvellir National Park, and one of the country’s most cherished wonders. Snorkelling and diving in its crystal-clear waters is an experience that is both thrilling and relaxing, and it is now considered to be one of the top five dive sites in the world. It takes around an hour to reach Silfra from Reykjavík. 

Geography of Silfra

Silfra fissure opened in 1789, due to the movements of the tectonic plates that frame Þingvellir National Park. The North American and Eurasian plates, which run all the way through Iceland, separate at about 2 centimetres per year, and as they do, they tear open fissures in the land between them. 

Some of the ravines fill with water travelling underground through the porous lava fields in the area, originating from Langjökull glacier about 60 kilometres north. It can take the water up to a century to reach Silfra and this long filtration process results in the water being both extremely clear and drinkable.

Because the water travels underground, it maintains a constant temperature of two to three degrees Celsius and does not freeze over immediately at the source of the spring. Snorkelling and diving tours are thus open throughout the year.

The clarity of the water is what draws most visitors. The visibility can extend to over 100 metres, allowing you to see the canyon walls and bottom like you are floating over a great cathedral.

The last colour that water absorbs is blue, which means that when you look forward in Silfra, it is as if you are looking into an ethereal, vivid, azure world. The clarity also means that sun-rays refract through the surface of the water, creating rainbows on Silfra’s bed when the weather allows. 

Snorkelling in Silfra

Snorkelling in Silfra fissure is a highly enjoyable activity, but you must meet some prerequisites to be able to join. These are as follows:

• You must be able to swim
• You must be over 16
• You must be in good physical health
• You must be at least 145 centimetres and 45 kilograms
• If you are over sixty, you will need a medical waiver
• If you are over forty-five with a history of heavy alcohol use and pipe smoking, you will also need a waiver

The most common option for snorkelling is to conduct it in a drysuit. Drysuits work with a fluffy undersuit to keep your body free from water and insulated against the cold, making the task of swimming through the near-freezing temperature more than achievable. 

While drysuit snorkelling is the most comfortable and popular option, a few tours allow you to go through Silfra wearing a wetsuit. Wetsuits, made of neoprene, allow water to surround your body in a thin layer, that your body then heats up and uses to protect you. Though they grant you more flexibility, they are not so warm, so this should be done by the daring; you will also need to be at least 50 kilograms to snorkel in a wetsuit.

In all tours, you wear neoprene on your head and hands to allow for better mobility, a mask and snorkel, and a pair of fins, all of which are provided on site. The course of Silfra takes approximately forty minutes, and there is a gentle current throughout, meaning it requires minimal energy to traverse.

Diving in Silfra

Diving through Silfra gives an extra dimension to its beauty, as you will be able to look up and see the sun glistening upon the surface as you cruise through the crystal clear waters. However, considering the risks associated with diving in cold water and cumbersome equipment, all who partake must meet all the requirements above, as well as one of the following:

• You must be a qualified diver with a certification in a drysuit speciality, OR
• You must be a qualified diver with at least 10 logged dives in a drysuit conducted over the past two years, signed by an instructor or divemaster.

Þingvallavatn (anglicised to Thingvallavatn, ‘the Lake of the Fields of Parliament’) is a rift valley lake located roughly forty-minutes drive from Iceland’s capital city, Reykjavík.

Features of Thingvallavatn

Þingvallavatn is partially within the boundaries of Þingvellir National Park, Iceland’s oldest National Park and only one with UNESCO World Heritage Site status.

Covering an area of 84 square kilometres (32 square miles), Þingvallavatn is the largest natural lake in Iceland with its greatest depth measuring at 114 metres (374 feet). Þingvallavatn is situated on the Mid-Atlantic Rift, on a part of the ridge known as the Reykjanes Ridge.

The lake has only one outflow, the river Sog.

Of particular note to biologists and fishermen are the four morphs of Arctic Char that inhabit the lake. The lake’s char are an excellent example of species evolving to fit and adapt to a secluded environment; over ten thousand years, one species of Char has transformed into four different-sub branches. Other fish in the lake include the the Brown Trout and the Three-Spine Stickleback.

History and Geology

Þingvallavatn takes its name from the historical founding of the Alþingi, which occurred in 930 AD at what is now known as Þingvellir National Park. Þingvellir literally translates to ‘Fields of Parliament’.

The Alþingi was the first democratically elected representative parliament in world history (examples such as Ancient Athens were direct, not representative, democracies); Icelanders used to travel by foot or horseback simply to congregate at Þingvellir where they would hear the latest laws and judgements of the island.

Þingvellir National Park is also notable for its geology. Given its position on the Mid Atlantic Ridge, the park is one of the only places on the planet where visitors can see both the North American and Eurasian tectonic plates standing exposed from the earth.

Footpaths allow you to get up close and personal to the plates, standing right where the ancient settlers once did. In between the tectonic plates lies fields of dried volcanic rock, blanketed with a thick, yet fragile layer of Icelandic moss.

Scuba Diving in Thingvallavatn

Scuba diving around Þingvallavatn revolves around two sites, Silfra Fissure and Davíðsgjá (David’s Crack), the former being one of the most popular spots on the planet for snorkelling and underwater exploration.

Silfra Fissure is situated between the North American and Eurasian tectonic plates and is filled with crystal-clear glacial water originating from the Langjökull ice cap. The water measures at between two degrees Celsius all year round, with a slight current preventing the fissure from ever freezing over.

Davíðsgjá is found within Þingvallavatn and is often considered the darker and more dramatic cousin of Silfra Fissure, resembling the gorge formation so prevalent across the Mid Atlantic Rift.

Only certain tour operators provide tours into Davíðsgjá, so make sure to do some research beforehand if you are looking to access this dive site during your time in Iceland.