Yes and no.

Generally speaking, we know the cause of their disappearance. However, we're sorely lacking on specific details, and what we do have is almost entirely from conflicting accounts such as the perspective of the Dunmer (or, at the time, Chimer) who fought a war against the Dwemer. And even then, we don't know precisely the effect of their disappearance.

So here's a run-down for you. The Dwemer and Chimer had been allies when they repulsed a Nord invasion, and Nerevar of the Chimer was close friends with Dumac Dwarfking of the Dwemer for more than 250 years, from 1E416 to just prior to 1E700. However, Voryn Dagoth learned that the Dwemer had discovered the Heart of Lorkhan under the Red Mountain, and Chief Tonal Architect Kagrenac was planning to harness this divine artifact to power the Numidium. This is what lead to the War of the First Council.

So Nerevar and his lieutenants (including Vivec and Almalexia) lead an army of Dunmer to assault the Red Mountain and force their former friends and allies to stop meddling with the heart of a god. Accounts of the battle differ. Some say the Chimer were losing the battle when Kagrenac used the tools on the Heart. Others say the Chimer were achieving a decisive victory and Kagrenac acted out of desperation. Either way, we know that the battle culminated in Kagrenac attempting to use the Heart, with the result that every Dwemer on Nirn disappeared entirely. (Events immediately following the battle and later attempts to utilize the Heart are a topic for another time.)

What actually happened to the Dwemer is almost entirely unknown. Some of what we know comes from Yagrum Bagarn, the last known living Dwemer. He survived because he was on another Plane at the moment when the Heart was activated. So we know that the effects were solely confined to Mundus. Much later, Arniel Gane believed that the Dwemer were still alive on another Plane far removed from the known Planes and could be contacted, but his experiments with recreating the circumstances of the Dwemer's disappearance only lead to his own disappearance.

One theory I have heard is that Kagrenac's experiments with the Heart attempting to create an artificial god in the form of the Numidium, instead lead to the entire race of Dwemer to undergo their own version of the Psijic Endeavor but fail to achieve CHIM, and so they all zero-summed simultaneously and were removed from reality by their own egos.

Hey! This an assignment in Mr. Artorius's class! Take this kind of question to /r/homeworkhelp.

Most conventional schools of thought on this postulate a precipitating external cause for their migration or destruction. Truthfully, this is probably the case. But I believe an internal, cultural cause is just as likely. My view, judging from the documents we have on Dwemer history, technology, and culture, is this: the Dwemer voluntarily extinguished their own existence, having achieved all of life's possible goods:

"Our extinction, however, would not be the outcome of an unnatural chastity, but would be a naturally occurring phenomenon once we had evolved far enough to apprehend our existence as so hopelessly pointless and unsatisfactory that we would no longer be subject to generative promptings. Paradoxically, this evolution toward life-sickness would be promoted by a mounting happiness among us. This happiness would be quickened by our following [the] evangelical guidelines for achieving such things as universal justice and charity. Only by securing every good that could be gotten in life, it is figured, could we know that they were not as good as nonexistence."

Brassworker Ligotti, the Conspiracy against the Dwemer Race, Scroll 7.

Plenty of theories, but no consensus as such, no. One of the better-known theories out there is this treatise, based on Demnevanni's pseudo-scientific work on theories about the nature of Dwemer tonal architecture, and concludes that the Dwemer were absorbed into the skin of the semi-mythical entity called "Anumidium". Other theories are that experiments by a tonal architect known as "Kagrenac" (but that appears to be a title rather than a name) led either to their transference into an alternate dimension, or to the entire race simultaneously achieving the state known to mystics as CHIM; Malier's antiquated theory that the Dwemeri use of telepathy allowed them to make a coordinated migration simultaneously; or a more recent suggestion, that the Dwemer were wiped out by the Falmer.

Part of the problem is that a large proportion of these theories rely on mysticism, or on unfounded suppositions about the nature of Dwemer technology. That doesn't make them impossible, of course, but as historians we have to work with evidence. You might retort that that gives us a heavy materialist bias; but still, without evidence, we're just speculating.

And there's a serious shortage of actual evidence. After the late Second Era, practically no work was done on the Dwemer for several centuries. Only at the end of the Third Era, several developments took place very quickly. Archaeological campaigns on Vvardenfell led to numerous studies on the Dwemer by figures like Antabolis, Cadiusus, and Elbert. Athellor's rediscovery of the long-lost text Fall of the Snow Prince in 3E 427 prompted intensive study of the relationship between the Dwemer and the Falmer: this led to the decipherment of Falmeris, and studies on both the Falmer and the Dwemer by recent authorities such as Uthrax and Calcelmo.

But when it comes to ancient sources on the Dwemer we're very much in the dark. We can't even be totally certain of the date of the disappearance of the Dwemer! Ghelein, writing in the early Second Era, dated it to 1E 700, and that's the conventional date; but Malier, writing a little later, dated it a few decades earlier in 1E 668 (see e.g. the publisher's notes to Ancient Tales of the Dwemer vol. 6). At the time Ghelein and Malier were writing, the University of Gwylim was the main centre for Dwemer scholarship, but the scholars there never arrived at a consensus. The modern agreement on 1E 700 is simply a result of Elbert taking Ghelein at his word; no one has ever seriously addressed the dating problem to my knowledge.

The whole topic is surrounded by deep methodological problems over how to interpret the evidence on the Battle of Red Mountain. There are several incompatible reports, and some historians have even resorted to the mystical idea of a "dragon break" to suggest that multiple timelines collided, or that time was manipulated by one of the various deities who were supposedly involved in the battle. Strictly speaking we can't rule that out, of course. But from the point of view of evidence, we've never yet found any material evidence of a real "dragon break".

If anything ever turns up in the archaeological record to suggest that dragon breaks are real, then we might have the beginnings of an explanation. As things stand, though, the "dragon break" theory is tantamount to positing a miracle.

There is no consensus. What we know is that they disappeared during the Battle of Red Mountain in 1E700, with all but a few who were otherwise bound vanishing. A popular theory relates the disappearance of the Dwemer to their arcane practices collectively known as "tonal architecture". As you are probably aware, many of the races of Tamriel past and present reject the Mundus, seeing Lorkhan as a trickster and betrayer of gods. But only two races actually carried this sentiment with them into the First Era, the other race being the Altmer. The Dwemer themselves were almost defined by their rejection of reality itself, and it is known that they sought to return themselves to a prior "divine state," as described by Baladas Demnevanni:

It was unfashionable among the Dwemer to view their spirits as synthetic constructs three, four, or forty creational gradients below the divine. During the Dawn Era they researched the death of the Earth Bones, what we call now the laws of nature, dissecting the process of the sacred willing itself into the profane. I believe their mechanists and tonal architects discovered systematic regression techniques to perform the reverse -- that is, to create the sacred from the deaths of the profane.

"Sacred willing itself into the profane" refers to the death of the gods that came before - the Earth Bones - to create the Mundus and it's population. It is believed that the Dwemer attempted to reverse this process, i.e. make gods from men. The results of failed experiments at anti-creation can be seen throughout Morrowind, Skyrim and Hammerfell in their mechanical constructs. The ultimate experiment would be to create a divine being of Dwemer origin and then leave the Mundus behind them. To do this, the Dwemer's greatest tonal architects worked with one of the most powerful artifacts known to have existed: the Heart of Lorkhan, literally the heart of a god. The mechanics of even manipulating the Heart are lost to time (as too is the Heart), so it's not likely that we will ever know why it was needed, but it is believed that the Dwemer as a whole would be bound to their new god, the Numidium, in the ultimate anti-creation. If this is what was attempted by Kagrenac during the Battle of Red Mountain, then it could explain why the (almost) entire Dwemer race vanished and why reports of the battle very wildly, as time itself is known to rend before the Brass God, as it did when Zurin Arctus activated it in the late Second Era, and as it did in the Third Era. But a definitive answer on the Dwemer may never be found.

There is some ambiguity. What's known for certain is that the disappearance of the Dwemer is related to the Heart of Lorkhan during the Battle of Red Mountain.

There are a few other theories. The text "The Fall of the Snow Prince" suggests that a civil war between the Dwemer and their Falmer slaves led to the destruction of the Dwemer. However, what's more likely is that something went wrong when they activated the Brass God, causing their disappearance, though what the exact mechanics were is unknown.