Iceland Travel Journal 冰島旅行日記 28 - 2019.10.19 Grábrók, Saxhóll Crater, Vatnshellir Lava Cave 格拉布鲁克火山口, 薩克斯霍爾火山口, 瓦汀舍利爾熔岩洞穴

Day 6's Notes - Continued 繼續第六天的雜記

Grábrók 格拉布鲁克火山口

The Grábrók volcanic crater is a prominent geological feature in West Iceland, situated east of Lake Hreðavatn in the Borgarfjörður fjord, resting near the campus of Bifröst University. It is the largest of three craters that formed approximately 3,400 years ago in a fissure eruption. This fissure is relatively small, measuring only about 7 kilometers (4.3 miles) in length. Grábrók belongs to the extensive Ljósufjöll volcanic system, which stretches over 90 km (56 miles), making it one of Iceland's longest; the last activity recorded in this system was about 1,000 years ago.

The eruption resulted in the creation of the Grábrókarhraun lava field, which significantly altered the local landscape. This lava flow was responsible for damming the Norðurá River and pushing its course further east up the valley. Consequently, the lava also blocked a hollow, forming the basin for Lake Hreðavatn. The crater itself rises about 170 meters (558 feet) above the ground. It is a popular destination for hikers, with easy access provided by a footpath. Although the ascent is quite steep, steps have been constructed along part of the path to make the climb easier. Beautiful water streams emerge from the lava field in several locations, with the largest group found in Paradisarlaut.

格拉布羅克火山口是冰島西部一處顯眼的地質特徵，位於博爾加峽灣 (Borgarfjörður fjord) 赫雷達瓦特恩湖 (Lake Hreðavatn) 以東，靠近比弗羅斯特 (Bifröst) 大學校園。它是大約 3400 年前由裂縫噴發形成的三個火山口中最大的一個。這條裂縫相對較小，長度僅約 7 公里（4.3英里）。格拉布羅克火山口屬於綿延超過 90 公里（56 英里）的利奧蘇菲 (Ljósufjöll) 火山系統，這系統是冰島最長的火山系統之一；這系統最後一次有記錄的火山活動發生在約 1000 年前。

火山爆發形成了格拉布羅卡赫勞恩熔岩原，顯著改變了當地的地形。熔岩流阻塞了諾杜拉河 (Norðurá)，迫使其河道向東延伸至山谷深處。熔岩也堵塞了一個窪地，形成了赫雷達瓦特恩湖 (Hreðavatn) 的盆地。火山口本身高出地面約 170 公尺（558 英尺）。這裡是健行者的熱門目的地，有一條便捷的步道可以到達。雖然上山的路比較陡峭，但部分路段建了台階，方便攀登。美麗的溪流從熔岩原的多個地方湧出，其中最大的一組位於帕拉迪薩爾勞特 (Paradisarlaut)。

Photo Date: 2019.10.19

Atlantsolía 加油站

Saxhóll Crater 薩克斯霍爾火山口

Nestled on the Snæfellsnes Peninsula within the bounds of Snæfellsjökull National Park, Saxhóll Crater offers visitors an easily accessible encounter with Iceland's dynamic geology. Rising approximately 109 meters (358 feet), this distinctive volcanic formation is not a demanding climb thanks to a well-engineered, shallow metal staircase. This 396-step pathway gracefully winds around the slope, providing convenient access to the summit.

Saxhóll is geologically young, estimated to have formed between 3,000 and 4,000 years ago. It is believed to be the result of a single, highly energetic phreatomagmatic eruption—a violently explosive event occurring when hot magma interacts with water. While the formation actually consists of two craters, most visitors ascend the first due to its proximity to the road.

From the top, hikers are rewarded with sweeping panoramic views. The vantage point allows sightseers to take in the vast expanse of the Atlantic Ocean, the majestic ice cap of the Snæfellsjökull Glacier, and the rugged, expansive lava fields that characterize the peninsula. Saxhóll Crater is a prime example of the landscape-shaping power of volcanism in Iceland, a country situated directly atop the Mid-Atlantic Ridge where the Eurasian and North American tectonic plates meet, guaranteeing continuous geological activity.

薩克斯霍爾火山口坐落在斯奈菲爾斯內斯 (Snæfellsnes) 半島，位於斯奈菲爾斯冰川 (Snæfellsjökull) 國家公園內，為遊客提供了一個輕鬆近距離體驗冰島動態地質奇觀的機會。這座獨特的火山地形高約 109 公尺（358 英尺），由於有精心設計的緩坡金屬階梯，攀登起來並不費力。這條 396 階梯的步道蜿蜒環繞山坡，方便遊客輕鬆登頂。

薩克斯霍爾火山地質年代較新，估計形成於 3000 至 4000 年前。據說它是單次高能量蒸氣岩漿火山爆發 (phreatomagmatic eruption) 的結果——這種劇烈的爆炸性事件是發生在熾熱的岩漿與水相互作用時。雖然這火山實際上由兩個火山口組成，但由於第一個火山口靠近公路，大多數遊客都會攀登它。

從頂上俯瞰，健行者可飽覽壯麗的全景。從這個有利的位置，遊客可以飽覽浩瀚的大西洋、雄偉的斯奈菲爾冰川以及構成半島特色的崎嶇廣闊的熔岩原。薩克斯霍爾火山口是冰島火山活動塑造地形的絕佳例證。冰島位於中大西洋海嶺之上，歐亞板塊和北美板塊在此交匯，地質活動持續不斷。

Vatnshellir Lava Cave 瓦汀舍利爾熔岩洞穴

Vatnshellir is an ancient and accessible lava tube cave, forming a captivating geological feature that can be explored in Iceland. Created approximately 8,000 years ago, it is one of the country's oldest accessible lava tubes.

Like all such formations, Vatnshellir was born during a volcanic eruption when a stream of molten rock began to cool on its exterior, forming a solid crust. The still-flowing lava beneath this crust eventually drained away, leaving behind a long, hollow channel. This particular cave extends for 200 meters (656 feet) and reaches a maximum depth of 35 meters (114 feet).

Vatnshellir is considered easier to enter than its counterparts, such as Leiðarendi, as a staircase has been installed to descend into its depths. Inside the tube, the lava rocks showcase a vibrant spectrum of minerals: reds signify iron deposits, yellows indicate sulfur, and greens reveal copper.

Lava caving is available in Vatnshellir primarily during the summer months and requires a guided tour. On this journey through the cave, visitors gain fascinating insights into both Iceland's complex geology and its rich folklore, which includes tales of trolls reputedly making these hidden caves their homes.

Unfortunately, when we visited in October, the cave was closed, meaning we missed the opportunity to explore the fascinating lava tube and witness its ancient formations firsthand.

瓦汀舍利爾是一個古老且易於進入的熔岩管洞穴，是冰島一處引人入勝的地質奇觀，值得探索。它形成於大約 8000 年前，是冰島最古老的、可供遊客進入的熔岩管之一。

與所有此類地形一樣，瓦特恩謝利爾洞 (Vatnshellir) 也形成於火山爆發期間，當時一股熔岩流在其外部開始冷卻，形成一層堅硬的外殼。外殼下方仍在流動的熔岩最終排乾，留下了一條長長的空心通道。這個洞穴綿延 200 公尺（656 英尺），最深處達 35 公尺（114 英尺）。

相較於其他類似的洞穴（例如萊達倫迪 (Leiðarendi) 洞穴），瓦特恩謝利爾洞穴更容易進入，因為裡面安裝了通往深處的階梯。洞穴內部，熔岩石呈現絢麗多彩的礦物：紅色是鐵礦，黃色是硫，綠色則是銅。

瓦特恩謝利爾熔岩洞穴探險主要在夏季進行，必須參加導覽團。在洞穴探險過程中，遊客不僅可以深入了解冰島複雜的地質構造，還能領略其豐富的民間傳說，其中包括據說巨魔將這些隱密洞穴作為家園的傳說。

很可惜，我們十月去的時候，洞穴關閉了，我們沒福氣探索這迷人的熔岩管洞穴並親眼目睹它古老的地形。