Cryptic crossword No 2,038

Across

1. City upgradation to underwater vehicle for short is built-up. But one is not Australian built. (15)
2. Study of heat energy causes meteoric rhythms to go all over the place! (15)
3. Knight around Iodine package. (3)
4. Grab back, at last it's gone to the pub. (3)
5. Candidate? Nu-uh belongs to me Earl! (7)
6. Regularly woof if inactive. (3)
7. Stop perished resident. (3,4)
8. Starts unusual for ones Texan sighting? (3)
9. Pin number locking up award in charge of system. (7)
10. Another pick at peak. (3)
11. Spot Carl initially read out. (3)
12. Indians create minivans and start by mistake. (6,9)
13. Most likely Mel recalled at a shout. Why? It's questionably. (15)

Down

1. Two tasks missed the actual start and the bit at the bottom. How could they! (3,3)
2. Image old boy Jack from London district on the junk of a Titanic. (15)
3. Can murders -excluding A&Es- rise? (4)
4. Sign of incurable disease. (6)
5. Recognize girl I have elected to. (4,2,2)
6. Crash imprisoned careless DUI number 88. (6)
7. Amazing inaudible sights are identifiable. (15)
8. Spite new start by various years. (4)
9. Boxer face off against Little Ike (3)
10. E.G. thinks primarily of oneself. (3)
11. Book about unionist is known. (3)
12. Says former takes. (8)
13. Which one of you gets a weak house circuit? (3)
14. Oven pushed down by Ells thick books. (6)
15. Andrew Jackson's note left in between Ty. (6)
16. Around as I hear section tests. (6)
17. Never amidst ten operas. (4)
18. Measurement ending Missouri known scientific research. (4)