An avalanche boulder tongue is an accumulation of debris produced by snow

Snow

Snow is a form of precipitation within the Earth's atmosphere in the form of crystalline water ice, consisting of a multitude of snowflakes that fall from clouds. Since snow is composed of small ice particles, it is a granular material. It has an open and therefore soft structure, unless packed by...

 avalanches. Well developed avalanche boulder tongue usually develop below avalanche gullies due to successive avalanches over a long time span. The avalanche boulder tongues were first intensively investigated by Anders Rapp

Anders Rapp

Anders Rapp was a Swedish geomorphologist and geographer who first made a comprehensive study on avalanche boulder tongues. Most of Rapp's works were made in the Scandinavian mountains and Spitsbergen including the areas of Kärkevagge near Abisko and Kebnekaise.Studying under Filip Hjulström, Rapp...

 in the areas of Abisko

Abisko

Abisko is a village in northern Sweden, near the Abisko National Park located 4 km west of the village. It had 85 inhabitants as of 2005.-Transportation:...

 and Kebnekaise

Kebnekaise

Kebnekaise is the highest mountain in Sweden and Sápmi. The Kebnekaise massif, which is part of the Scandinavian Mountains, has two peaks, of which the southern, glaciated one is highest at above sea level at the latest time of measurement. The north top is free of ice...

 in Swedish Lappland.