The northern plains are generally flat and smooth with few craters.
 However, a few large craters do stand out.
 The giant impact crater, Lyot, is easy to see in the northern part of Ismenius Lacus.
 Lyot Crater is the deepest point in Mars's northern hemisphere.
 One image below of Lyot Crater Dunes shows a variety of interesting forms: dark dunes, light-toned deposits, and Dust Devil Tracks.
 Dust devils, which resemble miniature tornados create the tracks by removing a thin, but bright deposit of dust to reveal the darker underlying surface.
Light-toned deposits are widely believed to contain minerals formed in water.
Research, published in June 2010, described evidence for liquid water in Lyot crater in the past.

Many channels have been found near Lyot Crater.
 Research, published in 2017, concluded that the channels were made from water released when the hot ejecta landed on a layer of ice that was 20 to 300 meters thick.
 Calculations suggest that the ejecta would have had a temperature of at least 250 degrees Fahrenheit.
 The valleys seem to start from beneath the ejecta near the outer edge of the ejecta.
 One evidence for this idea is that there are few secondary craters nearby.
Few secondary craters were formed because most landed on ice and did not affect the ground below.
The ice accumulated in the area when the climate was different.
 The tilt or obliquity of the axis changes frequently.
 During periods of greater tilt, ice from the poles is redistributed to the mid-latitudes.
 The existence of these channels is unusual because although Mars used to have water in rivers, lakes, and an ocean, these features have been dated to the Noachian and Hesperian periods—4 to 3 billion years ago.
The northern plains are generally flat and smooth with few craters.  However, a few large craters do stand out.  The giant impact crater, Lyot, is easy to see in the northern part of Ismenius Lacus.  Lyot Crater is the deepest point in Mars's northern hemisphere.  One image below of Lyot Crater Dunes shows a variety of interesting forms: dark dunes, light-toned deposits, and Dust Devil Tracks.  Dust devils, which resemble miniature tornados create the tracks by removing a thin, but bright deposit of dust to reveal the darker underlying surface. Light-toned deposits are widely believed to contain minerals formed in water. Research, published in June 2010, described evidence for liquid water in Lyot crater in the past.
Many channels have been found near Lyot Crater.  Research, published in 2017, concluded that the channels were made from water released when the hot ejecta landed on a layer of ice that was 20 to 300 meters thick.  Calculations suggest that the ejecta would have had a temperature of at least 250 degrees Fahrenheit.  The valleys seem to start from beneath the ejecta near the outer edge of the ejecta.  One evidence for this idea is that there are few secondary craters nearby. Few secondary craters were formed because most landed on ice and did not affect the ground below. The ice accumulated in the area when the climate was different.  The tilt or obliquity of the axis changes frequently.  During periods of greater tilt, ice from the poles is redistributed to the mid-latitudes.  The existence of these channels is unusual because although Mars used to have water in rivers, lakes, and an ocean, these features have been dated to the Noachian and Hesperian periods—4 to 3 billion years ago.
Ismenius Lacus quadrangle