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GLACIER "BRENVA"
Risk type: glacier length changes, glacier flood and ice avalanches

Glacier list | Statistics
 

Type:  Valley glacier
Country:  Italy
Region:  Aosta Valley
Massif/Ice Cap:  Monte Bianco
Municipality:  Courmayeur
Municipality code:  
Location:  
 
Latitude (°, cent):  45.85 N
Longitude (°, cent):  6.91 E
Surface (km2):  8.057
Lenght (km):  7.64
Width (km):  
Min. altitude (m):  1415
Max. altitude (m):  4810
Orientation (°)  135
Slope (°)  21

EVENT:  Date  18/1/1997 -  Date quality:   

Type:  Ice avalanches
Description  2 mio m3 of rocks detached from "Sperone della Brenva" and "Col Moor" origined an enormous avalanche of snow on Brenva glacier; the rock-collapse originated approximately 1 km from the source area of the 1920 rock avalanche, and the slope scarp extended for 250 m, with a height of 330 m. The highest point of failed rock was at 3725 m. The rock-fall origined an enormous avalanche of snow, ice, and rocks (total volume of about 4 mio m3) that reached the below Val Veny; it covered 5.5 km of distance and 2285 m of difference of altitude, and the average inclination of the slopes covered was 20°.
Effects:  The avalanche reached the ski-resort of Val Veny, killing two skiers. The debris was spilled from the right lateral moraine and piled up on the valley nearby; forming a natural dam as much as 25 m high, which temporarily blocked the flow of the Dora Baltea river. On the opposite side of Veny valley, hundreds of conifers were thrown down because of the air wave, and an hotel was damaged.
Deaths(#)  2
Injuried (#)  0
Note  The first signals of instability of rock-mass were observed already in August 1996. On January 16th, 1997, 100.000 cubic meters of rock fell on Brenva glacier, but the consequent snow-avalanche stopped one km after. The main causes canbe found in the rock mass conditions, and the changing glacier-surface and rock-surface temperatures. The decrease in ice-thickness, which is taking place following the Little Ice Age (about since 1850), causes a significant decrease in the confining force on the surrounding rock mass due to the glacier. Freezing and thawing cycles leading to frost damage affect the temperature distribution within the rock walls with enhancement of the rock-mass degree of fracturing. Mainly during summers of 1992 and 1997, a number of rock failures have been reported on both flanks of Mount Blanc.

DAMAGES    

Type:  Buildings Description:
Type:  Trees Description:

BIBLIOGRAPHY 

Barla G., Dutto F., Mortara G., 2000 - Brenva Glacier Rock Avalanche of 18 January 1997 on the Mount Blanc Range, Northwest Italy. Landslide News, n. 13, p. 2 - 5.
Bottino G., Chiarle M., Joly André, Mortara G., 2002 - Modelling rock avalanches and their relation to permafrost degradation in glacial environments. Permafrost and periglacial processes, 13, p. 283 - 288.
Deline P., 2001 - Recent Brenva rock avalanches (Valley of Aosta): new chapter in an old story? Suppl. Geogr. Fis. Dinam. Quat., V, p. 55-63.
Funk M., 1999 - Eboulements de rochers et chutes de séracs sur le versant sud du massif du Mont Blanc. Mont Blanc e dintorni, n. 8 (16), 1999.

EVENT:  Date  24/7/1929 -  Date quality:   

Type:  Glacier flood (contain both lakes and water pocket)
Description  Emptying of an internal water pocket. Water outburst from a point of the glacier 150-200 m above "Chalet della Brenva", on July 22nd. But the phenomenon reached the maximum intensity in the night between July 23rd and 24th.
Effects:  The flood canalized in the stream coming from Toula and Entreves glacier, then overflew eroding a road, and destroying a stable of a small hut near Dora river. Several trees were swept away. Dora river eroded its banks, below Entrèves village.
Deaths(#)  0
Injuried (#)  0
Note  

DAMAGES    

Type:  Agricolture Description:
Type:  Buildings Description:
Type:  Roads Description:

BIBLIOGRAPHY 

Sestini A., 1930 - Osservazioni e ricerche sulle valli di Courmayeur. Memorie geologiche e geografiche di Giotto Dainelli. N.1, p. 256.

EVENT:  Date  8/9/1929 -  Date quality:   

Type:  Rock fall on glacier surface
Description  Great rock-fall on the glacier, from Gran Pilier d'Angle (around 4200 m).
Effects:  
Deaths(#)  0
Injuried (#)  0
Note  

DAMAGES    

Type:  None Description:

BIBLIOGRAPHY 

Dutto F., Mortara G., 1991 - Grandi frane storiche con percorso su ghiacciaio in Valle d'Aosta. Rev. Valdôtaine d'Hist Nat., 45, p. 21-35

EVENT:  Date  /7/1928 -  Date quality:   

Type:  Glacier flood (contain both lakes and water pocket)
Description  Emptying of an internal water pocket.
Effects:  The outburst broke the right lateral moraine, and origined two debris-flow: one running towards Peuterey hamlet, the second one towards "Châlets del Purtud", that were invaded by debris and rocks; here an horse was killed, but buildings were not severely damaged.
Deaths(#)  0
Injuried (#)  0
Note  

DAMAGES    

Type:  Agricolture Description:
Type:  Buildings Description:

BIBLIOGRAPHY 

Sestini A., 1930 - Osservazioni e ricerche sulle valli di Courmayeur. Memorie geologiche e geografiche di Giotto Dainelli. N.1, p.255-256.

EVENT:  Date  //1928 -  Date quality:   

Type:  Ice avalanches
Description  Fall of big rocks from medial moraine to the external side of the lateral one.
Effects:  
Deaths(#)  0
Injuried (#)  0
Note  

DAMAGES    

Type:  None Description:

BIBLIOGRAPHY 

Sestini A., 1930 - Osservazioni e ricerche sulle valli di Courmayeur Memorie geologiche e geografiche di Giotto Dainelli. N.1, p.217-290.

EVENT:  Date  //1925 -  Date quality:   

Type:  Glacier flood (contain both lakes and water pocket)
Description  Emptying of ice-dammed lake.
Effects:  
Deaths(#)  0
Injuried (#)  0
Note  

DAMAGES    

Type:  None Description:

BIBLIOGRAPHY 

, 1925 - "Le Mont Blanc" journal, 26/6/1925

EVENT:  Date  14/11/1920 -  Date quality:   

Type:  Rock fall on glacier surface
Description  An enormous collapse of rocks and ice from Grand Pilier d'Angle (at 4240 m asl.) origined an avalanche on Brenva glacier that covered 5,7 km (horizontal projection) in 2-3 minutes, and a difference of altitude of 2890 m. The slopes covered by avalanche had an average inclination of 27°. Four other rock-falls occurred few days later, on November 19th, involving a volume of rocks fifteen times bigger than those of November 14th. On the whole the rock and ice mass detached was 6-7 mio m3. Several collapses were also reported in the following years in the area of Grand Pilier d'Angle.
Effects:  The ice and rock avalanche of November 14th divided in two parts, one stopping near "Case della Brenva" (1540 m), the other on "Piano del Peuterey" (1500 m). The fourth rock-avalanche of November 19th reached the bottom of Veny valley, temporarily damming Dora di Veny river; the debris ascended the opposite slope, destroying 50 hectares of forest. The extended cover of detritus on the ablation tongue of the glacier inhibited melting of the ice, resulting in significant advance of the glacier front for the following twenty years (100 m in the firtst two years), whereas the other glaciers in the area exhibited appreciable retreat during this period.
Deaths(#)  0
Injuried (#)  0
Note  

DAMAGES    

Type:  Trees Description:

BIBLIOGRAPHY 

Barla G., Dutto F., Mortara G., 2000 - Brenva glacier rock.avalanche of 18 January 1997 on the Mount Blanc range, Northwest Italy. Landslide News, n. 13, p. 2-5.
Bottino G., Chiarle M., Joly A., Mortara G., 2002 - Modelling rock avalanches and their relation to permafrost degradation in glacial environments. Permafrost and periglacial processes, 13, p. 283 - 288.
Deline P., 2001 - Recent Brenva rock avalanches (Valley of Aosta): new chapter in an old story? Suppl. Geogr. Fis. Dinam. Quat., V, p. 53-63.
Dutto F., Mortara G., 1991 - Grandi frane storiche con percorso su ghiacciaio in Valle d'Aosta. Rev. Valdôtaine d'Hist. Nat., 45, p. 21-35
Funk M., 1999 - Eboulements de rochers et chutes de séracs sur le versant sud du massif du Mont Blanc. Mont Blanc e dintorni, n. 8 (16), 1999
Valbusa U., 1921 - La catastrofe del Monte Bianco e del Ghiacciaio della Brenva del 14 e 19 novembre1920. Boll. R. Soc. Geogr. It. N.58 (3-4), p.95-114; p.151-162.

EVENT:  Date  // -  Date quality:23-24/7/1929   

Type:  Glacier flood (contain both lakes and water pocket)
Description  Emptying of an internal water pocket.
Effects:  Destruction of several buildings.
Deaths(#)  0
Injuried (#)  0
Note  

DAMAGES    

Type:  Buildings Description:

BIBLIOGRAPHY 

Sestini A., 1930 - Osservazioni e ricerche sulle valli di Courmayeur. Memorie geologiche e geografiche di Giotto Dainelli. N.1, p.217-290.

EVENT:  Date  // -  Date quality:XVI century   

Type:  Glacier length changes
Description  
Effects:  Destruction of a village.
Deaths(#)  0
Injuried (#)  0
Note  

DAMAGES    

Type:  Buildings Description:

BIBLIOGRAPHY 

Virgilio F., 1883 - Sui recenti studi circa le variazioni periodiche dei ghiacciai. Bollettino del Club Alpino Italiano. N.17 (50), p.50-70

EVENT:  Date  // -  Date quality:1965-1970   

Type:  Glacier length changes
Description  The glacier tongue advanced of 50 meters in 5 years.
Effects:  
Deaths(#)  0
Injuried (#)  0
Note  

DAMAGES    

Type:  None Description:

BIBLIOGRAPHY 

Lesca C., 1972 - L'espansione della lingua terminale del ghiacciaio della Brenva in base ai rilievi fotogrammetrici del 1959, 1970 e 1971. Bollettino del Comitato Glaciologico Italiano. Serie seconda. N.19, p.96
Lesca C., 1986 - Situazioni di rischio in montagna dovute a valanghe, espansioni glaciali e frane. Atti Corso. La protezione civile in Italia. Varese, Maggio-Settembre 1985. Giardini, Pisa, p.37-47

EVENT:  Date  // -  Date quality:1810-18   

Type:  Glacier length changes
Description  The glacier advanced of about 1000 meters in 8 years.
Effects:  
Deaths(#)  0
Injuried (#)  0
Note  

DAMAGES    

Type:  None Description:

BIBLIOGRAPHY 

Cerutti A. V., 1977 - Variazioni climatiche, alimentazione ed oscillazioni glaciali sul massiccio del Monte Bianco. Bollettino del Comitato Glaciologico Italiano. Serie seconda. N.25, p.53-88