Publication Date:
2017-04-04
Description:
Etna’s 2001 basaltic lava flow provided a good example of the distal flow segment between the flow front and stable channel, across which the flow evolves from channel-contained to dispersed. This zone was mapped with meter precision using LIDAR data collected during 2004 and 2005. These data, supported by field mapping, show that the flow front comprised eight lobes each 10 to 20 m high. The flow front appears to have advanced not as a single unit, but as a series of lobes moving forward one lobe at a time. Primary lobes were centered on the channel axis and marginal lobes were off-axis. The lobes advanced as breakouts of low-yield-strength lava from the flow core of the stalled flow front. Marginal lobes were abandoned and contributed to marginal levees flanking the transitional channel. For Etna’s 2001 flow, the transitional channel is 140 m wide, 700 m long and fed a 240-m-long zone of dispersed flow; the change from stable to transitional channel occurred at a major reduction in slope. Above this, the stable channel is 5.2 km long, 55 to 105 m wide and bounded by 15- to 25-m-high levees, and the stable channel is located over a previous channel. In a final stage of activity, lava ponding at the break-in-slope that marks the terminus of the stable channel put pressure on the eastern levee, causing it to fail. Liberated lava then fed a final break-out to the east. Similar flow front-features occur at other volcanoes, indicating that similar processes are characteristic of dispersed flow zones.
Description:
Published
Description:
119-127
Description:
1.10. TTC - Telerilevamento
Description:
3.5. Geologia e storia dei vulcani ed evoluzione dei magmi
Description:
3.6. Fisica del vulcanismo
Description:
JCR Journal
Description:
reserved
Keywords:
Basalt lava
;
Channelised lava flow
;
Flow front
;
Zone of dispersed flow
;
Flow dynamics
;
LIDAR
;
Etna
;
04. Solid Earth::04.08. Volcanology::04.08.05. Volcanic rocks
;
04. Solid Earth::04.08. Volcanology::04.08.07. Instruments and techniques
;
04. Solid Earth::04.08. Volcanology::04.08.08. Volcanic risk
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
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