Arsia Mons Anomaly?, Recent Mars Express Imagery shows odd feature Options

[Hungry4info]

Is that a Plume on Arsia Mons?
https://scilogs.spektrum.de/go-for-launch/i...-on-arsia-mons/

Images of the Tharsis region show the emergence of a new prolonged feature that appears to cast a long shadow. It is not visible in this attached image from 06 August 2018.


Then we can see something newish near Arsia Mons (the vertical streak) in this image from 19 Sep 2018.


And then most striking is this image from 23 Sep 2018, where it appears that a significant shadow is cast (in the direction of the streak in the last image, admittedly).


I'm not familiar enough with Martian meteorology to know if this is just a normal occurrence, but it does look weird, at least to me. Hopefully someone will have ideas. If the answer to this is obvious then feel free to lock and/or delete the thread.