| File name : | 166 - Richard Becker |
| File size : | 1506179 bytes |
| File date : | 2015:01:17 21:52:10 |
| Camera make : | SONY |
| Camera model : | DSC-P73 |
| Date/Time : | 2007:07:27 21:59:22 |
| Resolution : | 2304 x 1728 |
| Flash used : | No |
| Focal length : | 6.0mm |
| Exposure tim : | 0.0050 s (1/200) |
| Aperture : | f/2.8 |
| ISO equiv. : | 100 |
| Whitebalance : | Auto |
| Metering Mod : | pattern |
| Exposure : | program (auto) |
| JPEG Quality : | 88 |
| ======= IPTC dat : | ======= |
| City : | %G |
| Record vers. : | 4 |
| Keywords : | Glaciers |
| DateCreated : | 20070727 |
| Time Created : | 215922-0900 |
| Byline : | Richard Becker |
| Headline : | Richard_Becker |
| Credit : | Richard Becker |
| (C)Notice : | Copyright Richard Becker and shared per http://creativecommons.org/licenses/by-nc-sa/3.0/ |
| Caption : | Who carved those scratches into the bedrock? Was it THAT rock, carried by the glacier? You may be forgiven for thinking so; after all, that was the photographer’s initial opinion and he has a master’s degree in glacial geology! Glaciers carry rock fragments in two locations: at the bottom of the glacier and on top of the glacier. Rocks at the bottom scratch the bedrock and in turn are scratched by it; thus they have their sides sanded down to quite smooth surfaces. Rocks on top of the glacier are broken into sharp-edged fragments by water alternately freezing and thawing within their cracks. This boulder has many sharp-edged sides and no smooth surfaces; hence it was carried upon the glacier and rocks carried that way cannot scratch the underlying bedrock. Despite initial appearances, this rock is innocent! |
|
|
|
