Lada Terra

Lada Terra, named for a Slavic goddess of Love, [1] is a major landmass near the south pole of Venus which is centered at 60°S and 20°E and has a diameter of 8,615 kilometres (5,353 mi).

The broad region of Lada Terra contains massive coronae, rift zones, and volcanic plains as well as many other features that scientists use to attempt to piece together the history of this complex planet.

The distinctive cross-cutting relationships found in the bedding of Lada Terra have been important in realizing relative ages of the extensional belts and coronae, as well as the complex tesserae features present planet-wide.

[3] In 1990 the Venus Radar Mapper revealed the largest outflow channel system on the planet located in the northern region of Lada Terra.

[6] In 2007, data retrieved from the Venus Express mission using the Visible and Infrared Thermal Imaging Spectrometer revealed high emissivity anomalies which is interpreted by many scientists to be a hotspot analogous to the Hawaii hot spot on Earth.

[6] The mantle upwelling associated with hot spot tectonism appears to be the dominant process which formed and evolved the Lada Rise.

However, using cross cutting relationships obtained from the radar data received from the missions to Venus has allowed scientists to draw complex correlations.

[3] As a result, shield volcanoes formed around the corona and began intense episodic volcanism, with the flows from these events now covering 48% of the Lada Terra region.

[3] These massive lava flows along with the suspected adjacent mantle upwelling slowly built and uplifted the Lada Rise some time after the initial formation of the Quetzalpetlatl Corona.

[6] Volcanism due to the formation of the Boala Corona (with its deposits cross cutting the previously mentioned structures) form the youngest lava flows observed and represents the latest episode of the evolution of the Lada Rise.

Expanded view of Lada Terra. Black dashed line bounds Lada Terra while the white encloses Lavinia Planitia . The Quetzalpetlatl Corona is in red and the Boala Corona in yellow. The Alpha-Lada belt is depicted as the jagged light blue line. Background image courtesy of NASA/JPL
The large oval feature in the lower half of the image is Quetzalpetlatl Corona, approximately 700 km (420 miles) in diameter. Tectonic activity is largely observed in a relatively narrow rim region, which in this image is defined by a complex lineated terrain that surrounds much of the corona. Bright and dark volcanic flows are seen throughout the corona and surrounding terrain. Small shield volcanoes, 1-20 km (0.6-12 miles) in diameter, are seen near the southern limit. Narrow linear troughs (seen in the image as bright lines) trend to the north-northwest of Quetzalpetlatl.
Outflow channels on Lada Terra, outlined in red with youngest flow extent depicted as the yellow dashed lines. The channel is about 20 kilometers wide. Lada Terra, southern hemisphere of Venus. Background image provided by NASA/JPL