File:ʻAʻā Lava, Thomas A. Jaggar Museum, Hawaiʻi Volcanoes National Park, Hawaii (4529376010).jpg
Original file (2,816 × 2,112 pixels, file size: 1.83 MB, MIME type: image/jpeg)
This is a file from the Wikimedia Commons. The description on its description page there is shown below.
Commons is a freely licensed media file repository. You can help. |
Summary
DescriptionʻAʻā Lava, Thomas A. Jaggar Museum, Hawaiʻi Volcanoes National Park, Hawaii (4529376010).jpg |
English: Lava refers both to molten rock expelled by a volcano during an eruption and the resulting rock after solidification and cooling. This molten rock is formed in the interior of some planets, including Earth, and some of their satellites. When first erupted from a volcanic vent, lava is a liquid at temperatures from 700 to 1,200 °C (1,292 to 2,192 °F). Up to 100,000 times as viscous as water, lava can flow great distances before cooling and solidifying because of its thixotropic and shear thinning properties.
A lava flow is a moving outpouring of lava, which is created during a non-explosive effusive eruption. When it has stopped moving, lava solidifies to form igneous rock. The term lava flow is commonly shortened to lava. Explosive eruptions produce a mixture of volcanic ash and other fragments called tephra, rather than lava flows. The word "lava" comes from Italian, and is probably derived from the Latin word labes which means a fall or slide. The first use in connection with extruded magma (molten rock below the Earth's surface) was apparently in a short account written by Francesco Serao on the eruption of Vesuvius between May 14 and June 4, 1737. Serao described "a flow of fiery lava" as an analogy to the flow of water and mud down the flanks of the volcano following heavy rain. ʻAʻā is one of three basic types of flow lava. ʻAʻā is basaltic lava characterized by a rough or rubbly surface composed of broken lava blocks called clinker. The Hawaiian word was introduced as a technical term in geology by Clarence Dutton. The loose, broken, and sharp, spiny surface of an ʻaʻā flow makes hiking difficult and slow. The clinkery surface actually covers a massive dense core, which is the most active part of the flow. As pasty lava in the core travels downslope, the clinkers are carried along at the surface. At the leading edge of an ʻaʻā flow, however, these cooled fragments tumble down the steep front and are buried by the advancing flow. This produces a layer of lava fragments both at the bottom and top of an ʻaʻā flow. Accretionary lava balls as large as 3 metres (10 feet) are common on ʻaʻā flows. ʻAʻā is usually of higher viscosity than pāhoehoe. Pāhoehoe can turn into ʻaʻā if it becomes turbulent from meeting impediments or steep slopes. The sharp, angled texture makes ʻaʻā a strong radar reflector, and can easily be seen from an orbiting satellite (bright on Magellan pictures). ʻAʻā lavas typically erupt at temperatures of 1000 to 1100 °C.
|
Date | |
Source | ʻAʻā Lava, Thomas A. Jaggar Museum, Hawaiʻi Volcanoes National Park, Hawaii |
Author | Ken Lund from Reno, Nevada, USA |
Camera location | 19° 25′ 11.56″ N, 155° 17′ 17.16″ W | View this and other nearby images on: OpenStreetMap | 19.419877; -155.288100 |
---|
Licensing
- You are free:
- to share – to copy, distribute and transmit the work
- to remix – to adapt the work
- Under the following conditions:
- attribution – You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use.
- share alike – If you remix, transform, or build upon the material, you must distribute your contributions under the same or compatible license as the original.
This image was originally posted to Flickr by Ken Lund at https://flickr.com/photos/75683070@N00/4529376010. It was reviewed on 9 January 2017 by FlickreviewR and was confirmed to be licensed under the terms of the cc-by-sa-2.0. |
9 January 2017
Items portrayed in this file
depicts
some value
15 April 2010
19°25'11.557"N, 155°17'17.160"W
File history
Click on a date/time to view the file as it appeared at that time.
Date/Time | Thumbnail | Dimensions | User | Comment | |
---|---|---|---|---|---|
current | 03:41, 9 January 2017 | 2,816 × 2,112 (1.83 MB) | Holly Cheng | Transferred from Flickr via Flickr2Commons |
File usage
The following page uses this file:
Metadata
This file contains additional information, probably added from the digital camera or scanner used to create or digitize it.
If the file has been modified from its original state, some details may not fully reflect the modified file.
Camera manufacturer | Canon |
---|---|
Camera model | Canon PowerShot A540 |
Exposure time | 1/60 sec (0.016666666666667) |
F Number | f/2.6 |
Date and time of data generation | 15:29, 15 April 2010 |
Lens focal length | 5.8 mm |
Orientation | Normal |
Horizontal resolution | 180 dpi |
Vertical resolution | 180 dpi |
File change date and time | 15:29, 15 April 2010 |
Y and C positioning | Centered |
Exif version | 2.2 |
Date and time of digitizing | 15:29, 15 April 2010 |
Meaning of each component |
|
Image compression mode | 5 |
APEX shutter speed | 5.90625 |
APEX aperture | 2.75 |
APEX exposure bias | −0.66666666666667 |
Maximum land aperture | 2.75 APEX (f/2.59) |
Metering mode | Pattern |
Flash | Flash fired, compulsory flash firing, red-eye reduction mode |
Keywords | Hawaii |