So, I've been thinking for a while regarding devil fruit awakenings. I find them to be a fascinating topic worth looking into, even though Oda is definitely going to eventually show us how all the types of fruits awaken. We know how Zoan and Paramecia "awaken", but we do not yet know how Logia types awaken, which is the reason for this discussion. Furthermore, since Oda will be taking his time to do so, I figure it might be in our best interest as a community to discuss and come upon a temporary solution as to how Logia awakenings work so that it will be available for everybody on the site using Logia-types to access should they want to use the awakening idea but they do not have an idea about how to explain it themselves. With that being said, I will kick this discussion off by submitting my own theory.
I believe Logia awakenings cause a Logia's powers to essentially take on a "will" of their own. Well, perhaps not exactly in those words. As Logia allow a user to create, control, and manifest as an elemental form of nature, it would make logical sense that the next step in this power would be that the true characteristic of "force of nature" becomes evident in the Logia's powers. A Logia's power expands rapidly, overtaking the area around them. A fire-type Logia would consume an entire land into flames, evaporating the moisture in the air, water sources nearby, causing the heat of the entire land to go up significantly (think of Yamamoto's Bankai, in other words). A wind-type Logia would create an entire land full of tornadoes and hurricanes overtaking the area around them.
However, it isn't just that simple. What I mean by a Logia Awakening is that their power takes on a will, or mind, of its own. It expands rapidly and behaves chaotically, like a true "force of nature", consuming everything and completely transforming the battlefield into utter chaos which represents their Logia's element.
My evidence to support this claim is Akainu vs. Aokiji. As we know, they fought a monumental battle on Punk Hazard lasting ten days which transformed the entire climate of the island. Now, we can simply say that the long-standing battle between Magma and Ice caused this to happen as the climate was slowly "conditioned", but I seriously doubt climate could change so rapidly so easily, over a mere ten days, and continue behaving like this even YEARS after their fight. Something doesn't add up there. My theory is that Aokiji and Akainu awakened their Logia powers and let them loose on the island, causing the island itself to be transformed into their devil fruit's element, but because their powers were at odds and trying to crush the other, the two forces of nature struggled to the point that the island became half-ice and half-magma. This may also explain why they had to fight on an entirely different island, to avoid causing permanent devastation to any Marine bases or otherwise.
Anyways, that's my take on it. I am curious to hear everybody else's theories as well as opinions on the theory I suggested abov