Untersee (Lake Constance)

For other uses, seeUntersee.

Untersee
View from an aeroplane aboveRickenbach(CH) of the Untersee and the island ofReichenau(D) withLake Überlingen(D), the northwestern part of theObersee(D/CH/A) behind.
Untersee Untersee Untersee Untersee Untersee
Location	–Baden-Württemberg(Germany) – Cantons ofThurgauandSchaffhausen(Switzerland)
Coordinates	47°41′42″N9°1′28″E
Primary inflows	Seerhein,Radolfzeller Aachand smaller streams
Primary outflows	High Rhine
Surface area	62 square kilometres (24 sq mi)
Average depth	13 metres (43 ft)
Max. depth	45 metres (148 ft)
Water volume	0.8 cubic kilometres (0.19 cu mi)
Shore length1	87 kilometres (54 mi)
Surface elevation	395.11 metres (1,296.3 ft)
Islands	Reichenau,theWerdislands
Settlements	Radolfzell am Bodensee
1Shore length isnot a well-defined measure.

TheUntersee(GermanforLower Lake), also known asLower Lake Constance,is the smaller of the twolakesthat together formLake Constance.The boundary betweenSwitzerlandandGermanyruns through it. The lake surrounds several islands, the largest beingReichenau Island.

Geography

Map showing theUntersee.To the East, theSeerheinand parts of theOberseeare visible.
Yellow: German state ofBaden-Württemberg,green: Swiss canton ofThurgau,red: SwissCanton of Schaffhausen,red line:Germany–Switzerland border

Map ofUnterseewith the different parts of the lake

ExtinctHegauvolcanoesHohentwiel(front) andHohenstoffeln(back) andZeller See

The Island of Reichenau, as seen from theSeerücken,withRheinseein the front andGnadenseein the back

TheRheinseenearBerlingen

The Lower Lake Constance measures 63 km²(24 sq mi) and is situated about 30 cm (12 in) lower than theObersee.TheRomanscalled itLacus Acronius.In the Middle Ages, the Upper Lake was calledBodamicus Lacus,orBodenseein German.At some point in time, this term began to include the Lower Lake, and a new term "Upper Lake" (in German:Obersee), was introduced for the larger lake.

The main tributaries are theSeerheinandRadolfzeller Aach.The source of the latter is theAachtopf,akarst springwhose waters mainly derive from theDanube Sinkhole,making theDanubeindirectly a tributary ofUnterseeand the Rhine, respectively.

The landscape surrounding the Untersee is very diverse. The Untersee contains two islands:ReichenauandWerd(near the transition to theHigh Rhine). In the northeast is the peninsulaBodanrück;in the northwest, theHegaulowlands with the peninsulaMettnau;in the west, the peninsulaHöri,with a mountain calledSchiener Berg,and in the south, theSeerücken,which reaches more than 90 m (300 ft) feet above the Untersee nearBerlingen.

Bordering the Lower Lake Constance are theSwisscantons ofThurgauandSchaffhausenand theGermanstate ofBaden-Württemberg.In contrast to theUpper Lake,the border between Germany and Switzerland across the Lower Lake is well defined. Municipalities on the Swiss side areGottlieben,Ermatingen,Salenstein,Berlingen,Steckborn,Mammern,EschenzandStein am Rhein.Municipalities on the German side areÖhningen,Gaienhofen,Moos am Bodensee,Radolfzell,Reichenau,AllensbachandConstance.

Three parts in the north of Lower Lake, surrounded by German territory, have names of their own:Zeller See(lit. 'Lake of Radolfzell'),Gnadensee(lit. 'Lake Mercy') andMarkelfinger Winkel(lit. 'nook of Markelfingen'). The part in the south, which borders Switzerland, is calledRheinsee(lit. 'Rhine Lake').

Zeller See

TheZeller Seeis the part between theMettnaupeninsula in the north, theHöripeninsula in the south and theIsland of Reichenauin the east. To the west lies the estuary of theRadolfzeller Aachand theHegau.In the east, there is a small island calledLiebesinsel(lit. 'Love Island') close to the Mettnau peninsula.

Gnadensee

TheGnadenseeextends fromAllensbachin the north and the Island of Reichenau in the south, from the tip of Mettnau in the west to the Reichenaucausewaywith its well-visiblepoplaravenue in the east. According to legend, the nameGnade(English:Mercy or Grace) of the lake comes from the time when thecourt housewas located on the Island of Reichenau. If a defendant was sentenced to death, the execution of the sentence could not be carried out on the island, but only on the mainland because the island was "holy ground". Therefore, the condemned man was brought by boat to the mainland in the direction of Allensbach, where the sentence could beGnade.Now, if the abbot wanted to pardon the condemned, he would ring a bell before the offender arrived on the other shore. This signaled to the executioner on the mainland, that prisoner had been pardoned. However, this story is unlikely to be true. A more probable theory is that the lake is named after Maria, "Our Lady of Mercy", as the church of the abbey on the island was dedicated to St. Mary and St. Mark.The town nameFrauenfeldin neighbouringcanton of Thurgaucan be similarly explained.

Markelfinger Winkel

TheMarkelfingen Winkelis the western end of the Gnadensee, between Markelfingen in the north, Radolfzell in the west and the Mettnau peninsula in the south.Its eastern boundary is at the level of the summitMettnauspitze.With its maximum water depth of 16 m, the Markelfingen Winkel is the shallowest part of the lake. It has a tributary: the Mühlbach, which drains theMindelsee.

Rheinsee

The mainly Swiss section of the lake south of the Island of Reichenau and its southwestern arm is known asRheinsee(lit. 'Lake Rhine'), not to be confused withSeerhein(lit. 'Rhine of the lake(s)'), which is the Upper and Lower Lakes connecting segment of the river Rhine). It is called theSeerheinbecause the current of the river follows exactly this path through the lake to the effluent of Lower Lake Constance in the Swiss town ofStein am Rhein,where theHigh Rhinestarts. At the end of the lake, there are three small islands, called theWerd Islands.Where theSeerheinflows into theRheinseethere is the island ofTriboldingerbohl.There used to be another island calledEntlibühl.The nature reserveWollmatinger Riedis also located in this area. Theborder between Germany and SwitzerlandfollowsRheinseein east-west direction.

See also

• Obersee (Lake Constance)
• Seerhein
• Bodanrück

Bibliography

• Patrick Brauns, Wolfgang Pfrommer:Nature Hiking Guide Untersee. Nature guide to the unique cultural landscapes in the western Lake Constance area. (Hiking, biking, inline skating, canoeing, boat tours),Naturerbe-Verlag Resch, Überlingen, 1999,ISBN3-931173-14-3.