Is it unusual to see haboobs travel over the Indian Ocean with shelf clouds on top? What conditions can bring all of this about?

By accident¹ I ended up on the Bytes Daily page Photographs 2013, part 1. I saw an interesting image who’s caption reads:

A white shelf cloud caps brownish dirt from a dust storm, or haboob, as it travels across the Indian Ocean near Onslow on the Western Australia coast in this handout image distributed by fishwrecked.com and taken January 9, 2013.

Haboob is described in Wikipedia as follows:

A haboob (Arabic: هَبوب‎, romanized: habūb, lit. ’blasting/drifting’) is a type of intense dust storm carried on an atmospheric gravity current, also known as a weather front. Haboobs occur regularly in dry land area regions throughout the world.

Question(s):

1. Is it rare or unusual for haboobs to travel across the Indian Ocean or other oceans?
2. Is it rarer or more unusual still for shelf clouds to appear over them?
3. What conditions are necessary to bring all of this about?

Video links from the Wikipedia article:

• YouTube: Arizona Haboob!
• Vimeo: The Phoenix Haboob of July 5th, 2011

---

¹I was doing a reverse image search looking for a larger size of the photo of Earth, Venus and Mars amidst the rings of Saturn when Cassini was in Saturn’s shadow, and ended up on this page.

---