What is this second smaller runway next to London City Airport? I was looking at London City Airport (EGLC) on Google Maps today when I noticed the remains of a very small runway marked 10/28 just across the water from City Airport's main runway. It can be seen here.

To my surprise I couldn't find any mention of this small runway after searching online and looking into the history of the airport. Using the Google Earth historical imagery feature the earliest image I could find that included the runway was 2008, so I assume it was built some time between 2006 and 2008.

Can anybody tell me what this short runway is for?
Good Spot! That was a temporary runway for the Red Bull Air Race:

https://www.forgottenairfields.com/airfield-london-redbull-airstrip-1429.html

You can see "RB" at the eastern end on your satellite imagery