Brocken (), also sometimes referred to as Blocksberg, is a mountain near Schierke in the German state of Saxony-Anhalt, between the rivers Weser and Elbe. The highest peak in the Harz mountain range, and in Northern Germany, it is subalpine, yet has a microclimate resembling that of mountains nearly higher. The elevation above its tree line tends to have snowcover from September to May, and mists and fogs shroud it up to 300 days a year. The mean annual temperature is only . It is the easternmost mountain in northern Germany; the next prominent elevation directly to its east is in the Ural Mountains in Russia.
Brocken has always played a role in legends and has been connected with witches and devils; Johann Wolfgang von Goethe took up the legends in his two-part tragic play Faust. The Brocken spectre is a common phenomenon on this misty mountain, where a climber's shadow cast upon fog creates eerie optical effects.
Today Brocken is part of Harz National Park and hosts a historic botanical garden of about 1,600 alpine mountain plants. A narrow-gauge steam railway, the Brocken Railway, takes visitors to the railway station at an elevation of .
FM-radio and television broadcasting make major use of Brocken. The old television tower, the Sender Brocken, is now used as hotel and restaurant. It also has an observation deck, open to tourists.
Geography
Location Brocken rises over Harz National Park in the district of Harz, whose main town of Wernigerode lies about east-northeast of the mountain. The state boundary with Lower Saxony runs past Brocken some to the west. At the south-eastern foot of Brocken lies the spa resort of Schierke.
Somewhat to the north below the summit of Brocken is a reservoir, 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 Brocken is treeless, but vegetated with dwarf shrubs.
Summit and subpeaks The highest point on Brocken reaches an elevation of (). Its subpeaks include the Heinrichshöhe (), Königsberg () and Kleiner Brocken ("Little Brocken") ().
Before 1989, the height of Brocken was recorded in almost all the relevant maps and books as (). A survey of the summit at the beginning of the 1990s based on the current reference system, however, gave the height as . In order to provide a reference point for the old data, granite boulders were set in the mid-1990s on the highest point of Brocken to a height of approximately 1143 m, and a benchmark of "1142 m" was established on them.www.harzlife.de accessed on 13 July 2010.
Geology From a geological point of view, 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 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 Brocken, together with 76 other interesting geotopes, were designated as a "National Geotope".Friedhart Knolle, Béatrice Oesterreich, Rainer Schulz und Volker Wrede: Der Harz. Geologische Exkursionen. Perthes-Exkursionsführer, Justus Perthes Verlag Gotha, Gotha 1997
Climate
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 Brocken is like that of the alpine zone or even that of Iceland. 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 .
Due to its significant height difference compared with the surrounding terrain, Brocken has the highest precipitation of any point in northern central Europe, with an average annual precipitation (1961–1990) of . Its average annual temperature is .DWD – Klimadaten Mittelwerte accessed on 8 October 2010
Brocken weather station has recorded the following extreme values:110 Jahre Wetterbeobachtungen auf dem Brocken accessed on 8 October 2010 Its highest temperature was on 25 July 2019. Its lowest temperature was on 1 February 1956. In 1973 it had 205 days of snow cover. Its greatest depth of snow was on 14 and 15 April 1970. Its highest measured wind speed was on 24 November 1984. Its greatest annual precipitation was in 1981. Its least annual precipitation was in 1953. The longest annual sunshine was 2004.5 hours in 1921. The shortest annual sunshine was 972.2 hours in 1912. Brocken also holds the record for the greatest number of days of mist and fog in a single calendar year in Germany, 330 in 1958,DWD Weltrekorde - Nebel accessed on 8 October 2010 and has an average of 120 days of snowfall per year.
Flora
The harsh climate of 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. Brocken is the only mountain in Germany's Central Uplands whose summit lies above the natural 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 Brocken, but also high mountain flora from other regions and countries.
Amongst the rare species of Brocken that are found nowhere else in northern Germany and which occur above about () 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 grass (Anthoxanthum nipponicum), the alpine lady's mantle (Alchemilla alpina) and the alpine clubmoss (Diphasiastrum alpinum).
On the raised bogs around the summit of Brocken there are typical bog species like cottongrasses, sundews, dwarf birch (Betula nana) and the black crowberry, which is also referred to here as Brocken myrtle (Brockenmyrte).
Fauna
Several animal species have adapted to the conditions of life on 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 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.
History
Ascent, construction and use The first documented ascent of Brocken was 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 on the southern slope, named Heinrichshöhe after his son Henry (Heinrich) Ernest. The first inn on the summit of Brocken 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.A comprehensive account of this famous Gaussian survey may be found, for example, in Charles Kittel et al., Berkeley Physik Kurs 1, Mechanik, 5., verbesserte Auflage, Brunswick/Wiesbaden, 1991, p. 5, (Scan at GoogleBooks) A measurement carried out by the military staff of Prussia in 1850 found Brocken's height to be at its present level of . 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 granted by Count Otto of Stolberg-Wernigerode. It was Germany's first Alpine garden.
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 (). Its gauge is . In 1935 the Deutsche Reichspost made the first television broadcast from 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 Brocken, together with 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, Brocken was occupied by US troops. As part of the exchange of territory (specified at the Yalta Conference), the mountain was transferred to the Soviet occupation zone. Before the Americans left Brocken in 1947, however, they disabled the rebuilt weather station and the television tower.