Venus Crater Database

Catagories Included in the Database

Modification State

Larger versions of most sample images are available by selecting either the modification state image or crater name. The size of the larger image is given in kilobytes (kb). Large images are all at a scale of 225 m/pixel. The images retain the full radiometric calibration [Pettengill and others, 1991].

[Important Note: The modification state of the impact craters on the data base is subject to individual interpretation and bias of the authors. Note also that many craters on the data base have been assigned modification state designations that are a combination of two or more of the individual symbols shown below. For example, the crater Heloise designated vhp1 in the data base (Heloise shown below) represents a slightly fractured crater (f1) which has been heavily embayed by volcanic lava plains (vh) during the last global resurfacing event (p).]

[Important Note: The symbol p used ALONE in the Modification State column of the table ALWAYS represents a pristine (essentially unaltered) crater. However, when p is used in combination (as shown above for the crater Heloise) with other symbols in the Modification State column, it NEVER MEANS PRISTINE. Here, it symbolizes (in abbreviated form) a lava-embayed crater that is interpreted to have been embayed by lava plains deposits during the last global resurfacing episode - not subsequent to it.]

Examples of the basic states of impact crater modification used are:

	p, pristine--essentially unaltered crater ejecta and fluidized outflow deposits, where present (Chadwick and Schaber, 1993) (see notes above). Stuart (69 km diameter; 30.79°S, 20.22°E). (790 kb)
	vs, slightly embayed--crater with ejecta slightly embayed by volcanic lava. Ketzia (14.6 km diameter; 3.98°N, 300.50°E). (29 kb)
	vm, moderately embayed--crater with ejecta moderately embayed by volcanic lava. Bernadette (12.8 km diameter; 46.64°S, 285.6°E). (40 kb)
	vh, heavily embayed--crater with rim, ejecta (and often floor) heavily embayed by volcanic lava. Raisa (13.5 km diameter; 27.5°N, 280.3°E). (29 kb)
	vh3, heavily embayed and fractured--crater heavily embayed with volcanic lava and is heavily fractured. Baranamtarra (25.5 km diameter; 17.94°N, 267.80°E). (112 kb)
	vhp1 --crater that has a slightly fractured rim and has had its ejecta and rim heavily embayed (flooded) by lava plains that are interpreted to have been deposited during the last global resurfacing episode. Heloise, a doublet crater (16 km and 38 km diameters; 40.0°N, 51.9°E). (88 kb)
	f1, slightly fractured--crater estimated visually to have less than 50% of the crater floor, wall, and rim deposits affected by fractures (evidence of low to moderate local or regional extension). Missing Magellan orbits (black) appear at bottom. Wheatley (74.8 km diameter; 16.62°N, 268.03°E). (549 kb)
	f2, heavily fractured-- crater estimated visually to have more than 50% of its floor, wall, and rim deposits affected by fractures (evidence of moderate to moderately high, local or regional extension). Tubman (42.9 km diameter; 23.63°N, 204.57°E). (189 kb)
	f3, greatly disrupted--crater that is greatly disrupted; ejecta, rim and floor have been very degraded by fracturing with considerable extension. Balch (40-km diameter; 29.90°N, 282.91°E). (135 kb)
	fc1, compressed fracture--crater that has been slightly fractured (f1) by one or more compressive faults (fc). Barrymore (57-km diameter; 52.34°S, 195.68°E). (279 kb)
	e, ejecta mantled--crater mantled by ejecta from younger impact crater nearby. Alimat (13.5-km diameter; 29.5°S, 205.9°E). (29 kb)