The Slano Blato Landslide (), or the Salt Mud Slide, is a periodic landslide in Slovenia that is triggered approximately once a century.Kovač, Mirko, & Marko Kočevar. 2001. Plaz Slano Blato nad Lokavcem pri Ajdovščini. UJMA 14–15: 122–129. (with photos, maps) Although around 8,000 active landslides are present in Slovenia, the Slano Blato Landslide stands out as one of the most serious in terms of the damage it has caused.Komac, Blaž & Matija Zorn. Pobočni procesi in človek. Ljubljana: Založba ZRC.
The landslide is located on the southern edge of the Trnovo Plateau of the Dinaric Alps, below Mount Čaven and Little Mountain () next to the Platna mountain pasture.Platna Pasture on Geopedia It is moving along Grajšček Creek (which also originates in the landslide itselfSavnik, Roman, ed. 1968. Krajevni leksikon Slovenije, vol. 1. Ljubljana: Državna založba Slovenije. p. 24.) toward the settlement of Lokavec near Ajdovščina. It is long and wide, covering approximately between the elevations of . Zorn, Matija, Blaž Komac, Milan Orožen Adamič, & Karel Natek. 2008. Zemeljski plazovi v Sloveniji. Ljubljana: Založba ZRC, p. 39. Its maximum flow rate was recorded at /day.
Name The name of the landslide area was recorded as Blatna ('muddy') in 1881. The origin of the designation 'salt(y)' (Slovene slan) is uncertain. A local folk belief states that the high cleanup cost of the landslide resulted in an exorbitant cost (cf. Slovene zasoliti 'to over-salt'; metaphorically, 'to charge excessively'). However, the landslide bore the designation 'salt(y)' before any cleanup efforts were ever made.Rosana Rijavec. 2009. "Plaz Slano blato kljub sanaciji ne miruje". Večer (30 January).
Other locals state that sheep used to wander down to the area from nearby pastures, where they would lick the mud as a natural salt lick. This basis for the name's origin is supported by the fact that chemical analysis of the water at the landslide has shown it to have a very high mineral content, including sodium sulfate, also known as Glauber's salt.Benko, Igor. 2011. Zgodovinski pregled intervencij na plazu Slano blato. Paper presented at the conference Šukljetovi dnevi, Ajdovščina, 30 September 2011. (with photos, map)
History and activity Oral tradition regarding the landslide goes back four centuries, connecting it to the construction of a small church dedicated to Saint Urban on the slope of Mount Čaven above Lokavec and below the landslide. Saint Urban was invoked as a protector against natural disasters, and particularly with regard to a lake that people believed was hidden inside Mount Čaven that threatened to flood the valley.Slokar, Boris. "Sprehod do sv. Urbana" (with photos, map)
A 1789 source by Belsazar Hacquet mentioned the landslide, describing its debris flow in 1786. It was described again in an 1887 reportFifer Bizjak, Karmen, & Andreja Zupančič-Valant. 2007. Rheological investigation for the landslide Slano Blato near Ajdovščina (Slovenia). Geologija 50: 121–129, p. 121. that discussed the landslide event of 20 October 1885, in which 30 m of the road from Ajdovščina to Gorizia was destroyed. Cleanup efforts and landslide mitigation measures were carried out by Austrian authorities in 1903.Medvešček, Peter. 1904. Opis Sv. Križa. Gorica.
In November 2000, heavy rain and warm weather triggered the Slano Blato Landslide, which buried about of grassland and forest. A secondary flow was triggered in September 2001. The landslide stopped moving after this and is currently considered stable. Following these events, an access road was built and of material was removed from the lower part of the landslide and deposited north of the Ajdovščina Airport.
References
External links Platna Pasture on Geopedia, showing the adjacent (unlabeled) Slano Blato Landslide