Brocken

The Brocken rises over the Harz National Park in the district of Harz, whose main town of Wernigerode lies about 12 kilometres (7.5 mi) east-northeast of the mountain. The state boundary with Lower Saxony runs past the Brocken some 2 km (1.2 mi) to the west. At the southeastern foot of the Brocken lies the spa resort of Schierke.

Somewhat to the north below the summit of the Brocken is a reservoir, the Brockenteich, constructed in 1744. On or near the mountain are the source areas of the rivers Bode, Ecker, Ilse and Oder. The rounded summit of the Brocken is treeless, but vegetated with dwarf shrubs.

The highest point on the Brocken reaches an elevation of 1,141.1 m above sea level (NN) (3,744 ft). Its subpeaks include the Heinrichshöhe (1,040 m or 3,410 ft), Königsberg (1,034 m or 3,392 ft) and Kleiner Brocken ("Little Brocken") (1,018 m or 3,340 ft).

Before 1989 the height of the Brocken was recorded in almost all the relevant maps and books as 1,142 m above NN (3,747 ft). A survey of the summit at the beginning of the 1990s based on the current reference system, however, gave the height as just 1,141.1 m (3,744 ft). In order to provide a reference point for the old data, in the mid-1990s granite boulders were set on the highest point of the Brocken, which not only matched the old given height, but exceeded it by about a metre. A bench mark of "1142 m" was recorded on the summit stone. This height on the upper plate refers to the line on the lower plate.[1]

From a geological point of view the Brocken and its surrounding terrain, the Brocken massif, consists mainly of granite (called Brocken granite), an igneous rock. The granitic plutons of the Harz – the Brocken, Ramberg and Oker plutons – emerged towards the end of the Harz mountain-building phase of the Upper Carboniferous, about 300 million years ago. First, alkaline magma intruded into the overlying sediments, crystallized out and formed gabbro and diorite massifs, such as the Harzburg gabbro. A little later, silica-rich granitic magma rose, some intruding into voids and gaps in the older rocks, but most being created by the melting of existing sediments. On the boundary between granite and host rock, the so-called contact zone, a great variety of transitions may be seen. For example, the summit of the Achtermannshöhe consists of contact-metamorphosed hornfels of the contact zone that, here, lies over the Brocken granite. The subsequent erosion of the Harz mountains that followed the uplifting of the Harz during the Upper Cretaceous saw the disappearance of the protective hornfels summit, thus exposing the granite that had crystallized underground during the Upper Carboniferous. The alleged hardness of Brocken granite is not the reason for the height of the mountain, but the geological fact that it was well protected by its weather-resistant hornfels crest for a long time before erosion set in.

Only in recent geological times, since the tertiary period, did the typical, rounded, spheroidal weathering of granite outcrops and granite boulders of the Brocken take place. Such blockfields are very rare in Central Europe outside the Alps and are subject to conservation measures. They originated mainly under periglacial conditions, i.e. during the course of the ice ages, and their retreat. Today's blockfields of Brocken granite, as well as other rocks in the Harz National Park, particularly in the Oker valley, are therefore at least 10,000 years old. Physical weathering, such as frost shattering, has played a key role in their formation, resulting in giant piles of loosely stacked rocks. In 2006, the granite blockfields of the Brocken, together with 76 other interesting geotopes, were designated as a "National Geotope".[2]

Climatic diagram for 1961-1990 normals

Winter landscape (2003)

Brocken tower in winter (2001)

The Brocken is a place of extreme weather conditions. Due to its exposed location in the north of Germany its peak lies above the natural tree line. The climate on the Brocken is like that of an alpine location or even that of Iceland's 1,600–2,200-metre (5,200–7,200 ft) zone. This is due to its short summers and very long winters, with many months of continuous snow cover, strong storms and low temperatures even in summer. The summit, however, does not have an alpine climate, as the average summer temperature is above 10 °C (50 °F).

Due to its significant height difference compared with the surrounding terrain the Brocken has the highest precipitation of any point in northern central Europe, with an average annual precipitation (1961–1990) of 1,814 millimetres (71.4 in). Its average annual temperature is 2.9 °C (37.2 °F).[3]

The Brocken weather station has recorded the following extreme values:[4]

• Its highest temperature was 29.0 °C (84.2 °F) on 20 August 2012.
• Its lowest temperature was −28.4 °C (−19.1 °F) on 1 February 1956.
• In 1973 it had 205 days of snow cover.
• Its greatest depth of snow was 380 cm (150 in) on 14 and 15 April 1970.
• Its highest measured wind speed was 263 km/h (163 mph) on 24 November 1984.
• Its greatest annual precipitation was 2,335 mm (91.9 in) in 1981.
• Its least annual precipitation was 984 mm (38.7 in) in 1953.
• The longest annual sunshine was 2004.5 hours in 1921.
• The shortest annual sunshine was 972.2 hours in 1912.

The Brocken also holds the record for the greatest number of days of mist and fog in a single calendar year in Germany, 330 days in 1958,[5] and has an average of 120 days of snowfall per year.[6]

Brocken: treeline

The harsh climate of the Brocken makes it a habitat for rare species. The mountain's summit is a subalpine zone with flora and fauna almost comparable to those of north Scandinavia and the Alps. The Brocken is the only mountain in Germany's Central Uplands whose summit lies above the treeline, so that only very small spruce grow there and much of it is covered by a dwarf shrub heathland. In the Brocken Garden, established in 1890, flora are nurtured by national park employees; visitors are allowed to view it as part of regular guided tours. The garden does not just display plants from the Brocken, but also high mountain flora from other regions and countries.

Amongst the typical species of the Brocken that are rarely if ever found elsewhere in North Germany and which occur above about 1,050 m above NN (3,440 ft) are the variant of the alpine pasqueflower known as the Brocken flower or Brocken anemone (Pulsatilla alpina subsp. alba), hawkweeds like the Brocken hawkweed (Hieracium negrescens) and the alpine hawkweed (Hieracium alpinum), vernal grasses (Anthoxanthum), the lady's mantle (Alchemilla), the tormentil (Potentilla tormentilla), the alpine clubmoss (Diphasiastrum alpinum), the lichens, Iceland moss (Cetraria islandica) and reindeer lichen (Cladonia rangiferina). The crowberry is also referred to here as the Brocken myrtle (Brockenmyrte).

On the raised bogs around the summit of the Brocken there are e.g. cottongrasses, sundews and the dwarf birch (Betula nana).

The cranberry fritillary (Boloria aquilonaris)

Several animal species have adapted to the conditions of life on the Brocken. For example, the water pipit (Anthus aquaticus) and the ring ouzel both breed in the area around the summit.

The viviparous lizard occurs on the Brocken in a unique, dark-colored variant, Lacerta vivipara aberr. negra. The common frog (Rana temporaria) can also be found here. Insects are very numerous. There are many beetles including ground beetles such as Amara Erratica, and hundreds of species of butterfly. The cabbage white here produces only one generation per year compared with two in the lowlands.

Some mammal and bird species that occur here are relics of the ice age, including the northern bat (Eptesicus nils soni), the alpine shrew (Sorex alpinus) and the ring ouzel.

The first ascent of the Brocken was documented in 1572 by the physician and botanist, Johannes Thal from Stolberg, who in his book Sylva Hercynia described the flora of the mountain area. In 1736 Count Christian Ernst of Stolberg-Wernigerode had the Wolkenhäuschen ("Clouds Cabin") erected at the summit, a small refuge that is still preserved. He also had a mountain lodge built at the southern slope, named Heinrichshöhe after his son Henry (Heinrich) Ernest. The first inn on the Brocken summit was built around 1800.

Between 1821 and 1825 Carl Friedrich Gauss used the line-of-sight to the Großer Inselsberg in the Thuringian Forest and the Hoher Hagen mountain near Göttingen for triangulation in the course of the geodesic survey of the Kingdom of Hanover.[7] A measurement carried out by the military staff of Prussia in 1850 found the Brocken's height to be at its present level of 1,141.1 metres (3,744 ft). After the first Brocken lodge had been destroyed by a fire, a new hotel opened in 1862. The Brocken Garden, a botanical garden, was laid out in 1890 by Professor Albert Peter of Göttingen University on an area of 4,600 m² (50,000 sq ft) granted by Count Otto of Stolberg-Wernigerode. It was Germany's first Alpine garden.

View of the Brocken from the Heinrich Heine Way. In the foreground the Brocken Railway (2008)

View from the weather observation platform of the weather station on the Brocken peak (2006)

The narrow gauge Brocken Railway was opened on 27 March 1899. Brocken station is one of the highest railway stations in Germany lying at a height of 1,125 m above NN (3,691 ft). Its gauge is 1,000 mm (3 ft 3 ³⁄₈ in). In 1935 the Deutsche Reichspost made the first television broadcast from the Brocken using a mobile transmitter and, in the following year, the first television tower in the world was built on the mountain; carrying the first live television broadcast of the Summer Olympics in Berlin. The tower continued functioning until September 1939, when the authorities suspended broadcasting on the outbreak of World War II.

In 1937 the Brocken, together with the Wurmberg, Achtermann and Acker-Bruchberg were designated as the Upper Harz (Oberharz) nature reserve.

During an air attack by the United States Army Air Forces on 17 April 1945 the Brocken Hotel and the weather station were destroyed by bombing. The television tower, however, survived. From 1945 until April 1947, the Brocken was occupied by US troops. As part of the exchange of territorial (specified at the Yalta Conference) the mountain was transferred to the Soviet occupation zone. Before the Americans left the Brocken in 1947, however, they disabled the rebuilt weather station and the television tower.

The ruins of the Brocken Hotel were blown up in 1949. From 1948 to 1959 part of the Brocken was reopened to tourists. Although a pass was required, these were freely issued. From August 1961 the Brocken, which lay in East Germany's border zone, immediately adjacent to West Germany, was declared a military exclusion zone and was therefore no longer open to public access. Extensive military installations were built on and around the summit. The security of the area was the responsibility of the border guards of the 7th Schierke Border Company, which was stationed in platoon strength on the summit. For accommodation, they used the Brocken railway station. The Soviet Red Army also used a large portion of territory. In 1987, the goods traffic on the Brocken Railway ceased due to poor track conditions.

The Brocken was extensively used for surveillance and espionage purposes. On the summit were two large and powerful listening stations, which could capture radio traffic in almost all of Western Europe. One belonged to Soviet military intelligence, the GRU and was also the westernmost outpost of the Soviets in Germany; the other was Department III of the Ministry for State Security in the GDR. The listening posts were codenamed "Yenisei" and "Urian".[8] Between 1973 and 1976 a new modern television tower was built for the second channel of the GDR-TV. Today it is used by the public Zweites Deutsches Fernsehen (ZDF) television network. The Stasi (East German secret police) used the old tower until 1985, when they moved to a new building – now a museum. To seal the area, the entire Brocken plateau was then surrounded by a concrete wall, built from 2,318 sections, each one 2.4 tonnes (2.6 short tons) in weight and 3.60 metres (11.8 ft) high. The whole area was not publicly accessible until 3 December 1989. The wall has since been dismantled, as have the Russian barracks and the domes of their listening posts. Today the old tower beside the lodge again is home to a weather station of the Deutscher Wetterdienst.

Following the fall of the Berlin Wall beginning on 3 December 1989 the Brocken was again open to the public during a demonstration walk.[9] With German reunification there was a gradual reduction in border security facilities and military installations from 1990. The last Russian soldier left the Brocken on 30 March 1994. The Brocken summit was renaturalised at a cost of millions of euros. It is now a popular tourist destination for visitors to the Harz.

As a protected area since 1939 and due to the decades of restricted access the unique climate of the Brocken provided outstanding conditions. The massif is partly still covered with primary forest extremely rare in Germany. It provides perfect conditions for endangered and nearly extinct species like the Eurasian lynx, wildcats and capercaillies. The Brocken was therefore declared part of a national park in 1990.

The Wurmberg, Hohnekamm and Brocken (from left) from the Büchenberg near Elbingerode

The widespread use of the name "Brocken" did not occur until towards the end of the Middle Ages. Hitherto the region had just been described as the Harz. This was primarily because, until then, the focus had been mining.[10] The first record of a placename that resembles the present name of the mountain goes back, however, to the year 1176 when it is referred to as broke in the Saxon World Chronicle (Sächsische Weltchronik).[11] Another early written reference to the mountain, this time as the Brackenberg, appears in 1490 in a letter from Count Henry of Stolberg.[12] Other early documented names of the Brocken were, in 1401, the Brockenberg, in 1424 the Brocberg, in 1495 mons ruptus (Latin), in 1511 the Brogken and Brockin, in 1531 the Brogken, in 1540 the Brokenberg and, in 1589, the Brackenberg.[13] In Old Saxon-Germanic times, a large portrait of Wodin is supposed to have been found on the Brocken. In addition, animal and human sacrifices were offered by the Saxons to their supreme god, Odin, on the blockfields of the summit until they renounced them as part of their baptismal vows when Christianity spread to the region under Charles the Great.[14]

As far as the origin of the name is concerned, there are several interpretations: In the town records (Stadtbuch) of Osterwieck an entry for the Brocken was found in the year 1495 under the Latin name of mons ruptus, which means "broken hill".[11] Its Low German name, broken, as the mountain had become named in 1176 in the Saxon World Chronicle and also in English, means "broken". On the one hand, this explanation of its meaning can be attributed to the fact that the two mountains, "Kleiner Brocken" and "Großer Brocken", were formed by the breakup of a single massif.[10] On the other hand, its meaning may refer to the serious erosion of the mountain. In other words, it refers to the fact that the Brocken was eroded or "broken down" to its present size.[15]

But the most likely derivation of the name comes from the shape of the mountain as a whole. A brocken in German is a large, shapeless mass. The size of the Brocken may thus have given it its name. Since the term "block" has a similar meaning, this could also be the derivation of its alternative name, the Blocksberg.[10] The true origin of the name Blocksberg, however, should not be seen as "block" in the sense of "mass", but rather the German word block (as in block of wood) in witchcraft.[16]

Another theory holds that the name "Brocken" is derived from bruch, a word used in northern Germany for bog or moor, which commonly used to be spelt as bruoch or brok.[12] It is however doubtful that this fact was primarily responsible for its name.[10] Another possibility is that its name is derived from the fields of boulders strewn over the summit and the slopes of the mountain. This derivation for the name "Brocken" is, however, unlikely[15] because such blockfields are also found on other mountains in the Harz. Moreover, the regions concerned were hardly known at the time when the term was used.[10] Another presumption is based on the reference in a letter written in 1490 by Count Henry of Stolberg-Wernigerode, where he uses the term Brackenberg. However the suggestion that this referred to old, unusable timber, which was called bracken, is disputed.[12]

Since the 1930s various radio and television transmitters have been erected on the Brocken, see Brocken Transmitter.

Brocken House (Brockenhaus), the modern information centre for the Harz National Park, is located in the converted "Stasi Mosque" (Stasi-Moschee), a former surveillance installation for the Ministry for State Security. The historic antenna equipment in the dome may be visited. Behind the building is checkpoint No. 9 on the Harzer Wandernadel hiking trail network.

The extreme weather conditions of the Brocken are of special meteorological interest. From 1836 the Brockenwirt, who also ran the guest house and restaurant, kept meteorological records. The first weather station on the Brocken was built in 1895. Technically poor and too small, it was partially demolished in 1912 and replaced with a large stone construction, the Hellman Observatory, that was not completed until the First World War. In 1917 the academic and nature lover George Grobe took over running the observation post, his daughter supporting him until his death in 1935.[19] Today's weather station started life in 1939. Measurements were interrupted at the end of the Second World War as a result of military bombardment, but began again in 1947. On 16 March 2010 the Brocken Weather Station became a climate reference station to provide uninterrupted, long-term climatic observations.[20]